diff --git a/modules/openapi-generator/src/main/resources/php-nextgen/api.mustache b/modules/openapi-generator/src/main/resources/php-nextgen/api.mustache
index e08efd963782..ce84b768d951 100644
--- a/modules/openapi-generator/src/main/resources/php-nextgen/api.mustache
+++ b/modules/openapi-generator/src/main/resources/php-nextgen/api.mustache
@@ -131,10 +131,10 @@ use {{invokerPackage}}\ObjectSerializer;
      * {{.}}
      *
 {{/description}}
-{{#vendorExtensions.x-group-parameters}}
+{{#exts.x-group-parameters}}
      * Note: the input parameter is an associative array with the keys listed as the parameter name below
      *
-{{/vendorExtensions.x-group-parameters}}
+{{/exts.x-group-parameters}}
 {{#servers}}
 {{#-first}}
      * This operation contains host(s) defined in the OpenAPI spec. Use 'hostIndex' to select the host.
@@ -156,7 +156,7 @@ use {{invokerPackage}}\ObjectSerializer;
 {{/-last}}
 {{/servers}}
 {{#allParams}}
-     * @param  {{{dataType}}}{{^required}}|null{{/required}} ${{paramName}}{{#description}} {{.}}{{/description}}{{^description}} {{paramName}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
+     * @param  {{{dataType}}}{{#notRequiredOrIsNullable}}|null{{/notRequiredOrIsNullable}} ${{paramName}}{{#description}} {{.}}{{/description}}{{^description}} {{paramName}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
 {{/allParams}}
 {{#servers}}
 {{#-first}}
@@ -168,15 +168,15 @@ use {{invokerPackage}}\ObjectSerializer;
      *
      * @throws ApiException on non-2xx response or if the response body is not in the expected format
      * @throws InvalidArgumentException
-     * @return {{{vendorExtensions.x-php-doc-return-type}}}
+     * @return {{{exts.x-php-doc-return-type}}}
     {{#isDeprecated}}
      * @deprecated
     {{/isDeprecated}}
      */
     public function {{operationId}}(
-    {{^vendorExtensions.x-group-parameters}}
+    {{^exts.x-group-parameters}}
     {{#allParams}}
-        {{vendorExtensions.x-php-param-type}} ${{paramName}}{{^required}} = {{#defaultValue}}{{{.}}}{{/defaultValue}}{{^defaultValue}}null{{/defaultValue}}{{/required}},
+        {{exts.x-php-param-type}} ${{paramName}}{{^required}} = {{#defaultValue}}{{{.}}}{{/defaultValue}}{{^defaultValue}}null{{/defaultValue}}{{/required}},
     {{/allParams}}
     {{#servers}}
     {{#-first}}
@@ -185,14 +185,14 @@ use {{invokerPackage}}\ObjectSerializer;
     {{/-first}}
     {{/servers}}
         string $contentType = self::contentTypes['{{{operationId}}}'][0]
-    {{/vendorExtensions.x-group-parameters}}
-    {{#vendorExtensions.x-group-parameters}}
+    {{/exts.x-group-parameters}}
+    {{#exts.x-group-parameters}}
         array $associative_array
-    {{/vendorExtensions.x-group-parameters}}
-    ): {{{vendorExtensions.x-php-return-type}}}
+    {{/exts.x-group-parameters}}
+    ): {{{exts.x-php-return-type}}}
     {
-        {{^vendorExtensions.x-php-return-type-is-void}}list($response) = {{/vendorExtensions.x-php-return-type-is-void}}$this->{{operationId}}WithHttpInfo({{^vendorExtensions.x-group-parameters}}{{#allParams}}${{paramName}}, {{/allParams}}{{#servers}}{{#-first}}$hostIndex, $variables, {{/-first}}{{/servers}}$contentType{{/vendorExtensions.x-group-parameters}}{{#vendorExtensions.x-group-parameters}}$associative_array{{/vendorExtensions.x-group-parameters}});{{^vendorExtensions.x-php-return-type-is-void}}
-        return $response;{{/vendorExtensions.x-php-return-type-is-void}}
+        {{^exts.x-php-return-type-is-void}}list($response) = {{/exts.x-php-return-type-is-void}}$this->{{operationId}}WithHttpInfo({{^exts.x-group-parameters}}{{#allParams}}${{paramName}}, {{/allParams}}{{#servers}}{{#-first}}$hostIndex, $variables, {{/-first}}{{/servers}}$contentType{{/exts.x-group-parameters}}{{#exts.x-group-parameters}}$associative_array{{/exts.x-group-parameters}});{{^exts.x-php-return-type-is-void}}
+        return $response;{{/exts.x-php-return-type-is-void}}
     }
 
     /**
@@ -206,10 +206,10 @@ use {{invokerPackage}}\ObjectSerializer;
      * {{.}}
      *
 {{/description}}
-{{#vendorExtensions.x-group-parameters}}
+{{#exts.x-group-parameters}}
      * Note: the input parameter is an associative array with the keys listed as the parameter name below
      *
-{{/vendorExtensions.x-group-parameters}}
+{{/exts.x-group-parameters}}
 {{#servers}}
 {{#-first}}
      * This operation contains host(s) defined in the OpenAPI spec. Use 'hostIndex' to select the host.
@@ -231,7 +231,7 @@ use {{invokerPackage}}\ObjectSerializer;
 {{/-last}}
 {{/servers}}
 {{#allParams}}
-     * @param  {{{dataType}}}{{^required}}|null{{/required}} ${{paramName}}{{#description}} {{.}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
+     * @param  {{{dataType}}}{{#notRequiredOrIsNullable}}|null{{/notRequiredOrIsNullable}} ${{paramName}}{{#description}} {{.}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
 {{/allParams}}
 {{#servers}}
 {{#-first}}
@@ -249,9 +249,9 @@ use {{invokerPackage}}\ObjectSerializer;
     {{/isDeprecated}}
      */
     public function {{operationId}}WithHttpInfo(
-    {{^vendorExtensions.x-group-parameters}}
+    {{^exts.x-group-parameters}}
     {{#allParams}}
-        {{vendorExtensions.x-php-param-type}} ${{paramName}}{{^required}} = {{#defaultValue}}{{{.}}}{{/defaultValue}}{{^defaultValue}}null{{/defaultValue}}{{/required}},
+        {{exts.x-php-param-type}} ${{paramName}}{{^required}} = {{#defaultValue}}{{{.}}}{{/defaultValue}}{{^defaultValue}}null{{/defaultValue}}{{/required}},
     {{/allParams}}
     {{#servers}}
     {{#-first}}
@@ -260,13 +260,13 @@ use {{invokerPackage}}\ObjectSerializer;
     {{/-first}}
     {{/servers}}
         string $contentType = self::contentTypes['{{{operationId}}}'][0]
-    {{/vendorExtensions.x-group-parameters}}
-    {{#vendorExtensions.x-group-parameters}}
+    {{/exts.x-group-parameters}}
+    {{#exts.x-group-parameters}}
         array $associative_array
-    {{/vendorExtensions.x-group-parameters}}
+    {{/exts.x-group-parameters}}
     ): array
     {
-        $request = $this->{{operationId}}Request({{^vendorExtensions.x-group-parameters}}{{#allParams}}${{paramName}}, {{/allParams}}{{#servers}}{{#-first}}$hostIndex, $variables, {{/-first}}{{/servers}}$contentType{{/vendorExtensions.x-group-parameters}}{{#vendorExtensions.x-group-parameters}}$associative_array{{/vendorExtensions.x-group-parameters}});
+        $request = $this->{{operationId}}Request({{^exts.x-group-parameters}}{{#allParams}}${{paramName}}, {{/allParams}}{{#servers}}{{#-first}}$hostIndex, $variables, {{/-first}}{{/servers}}$contentType{{/exts.x-group-parameters}}{{#exts.x-group-parameters}}$associative_array{{/exts.x-group-parameters}});
 
         try {
             $options = $this->createHttpClientOption();
@@ -379,10 +379,10 @@ use {{invokerPackage}}\ObjectSerializer;
      * {{.}}
      *
 {{/description}}
-{{#vendorExtensions.x-group-parameters}}
+{{#exts.x-group-parameters}}
      * Note: the input parameter is an associative array with the keys listed as the parameter name below
      *
-{{/vendorExtensions.x-group-parameters}}
+{{/exts.x-group-parameters}}
 {{#servers}}
 {{#-first}}
      * This operation contains host(s) defined in the OpenAPI spec. Use 'hostIndex' to select the host.
@@ -404,7 +404,7 @@ use {{invokerPackage}}\ObjectSerializer;
 {{/-last}}
 {{/servers}}
 {{#allParams}}
-     * @param  {{{dataType}}}{{^required}}|null{{/required}} ${{paramName}}{{#description}} {{.}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
+     * @param  {{{dataType}}}{{#notRequiredOrIsNullable}}|null{{/notRequiredOrIsNullable}} ${{paramName}}{{#description}} {{.}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
 {{/allParams}}
 {{#servers}}
 {{#-first}}
@@ -421,9 +421,9 @@ use {{invokerPackage}}\ObjectSerializer;
     {{/isDeprecated}}
      */
     public function {{operationId}}Async(
-    {{^vendorExtensions.x-group-parameters}}
+    {{^exts.x-group-parameters}}
     {{#allParams}}
-        {{vendorExtensions.x-php-param-type}} ${{paramName}}{{^required}} = {{#defaultValue}}{{{.}}}{{/defaultValue}}{{^defaultValue}}null{{/defaultValue}}{{/required}},
+        {{exts.x-php-param-type}} ${{paramName}}{{^required}} = {{#defaultValue}}{{{.}}}{{/defaultValue}}{{^defaultValue}}null{{/defaultValue}}{{/required}},
     {{/allParams}}
     {{#servers}}
     {{#-first}}
@@ -432,13 +432,13 @@ use {{invokerPackage}}\ObjectSerializer;
     {{/-first}}
     {{/servers}}
         string $contentType = self::contentTypes['{{{operationId}}}'][0]
-    {{/vendorExtensions.x-group-parameters}}
-    {{#vendorExtensions.x-group-parameters}}
+    {{/exts.x-group-parameters}}
+    {{#exts.x-group-parameters}}
         array $associative_array
-    {{/vendorExtensions.x-group-parameters}}
+    {{/exts.x-group-parameters}}
     ): PromiseInterface
     {
-        return $this->{{operationId}}AsyncWithHttpInfo({{^vendorExtensions.x-group-parameters}}{{#allParams}}${{paramName}}, {{/allParams}}{{#servers}}{{#-first}}$hostIndex, $variables, {{/-first}}{{/servers}}$contentType{{/vendorExtensions.x-group-parameters}}{{#vendorExtensions.x-group-parameters}}$associative_array{{/vendorExtensions.x-group-parameters}})
+        return $this->{{operationId}}AsyncWithHttpInfo({{^exts.x-group-parameters}}{{#allParams}}${{paramName}}, {{/allParams}}{{#servers}}{{#-first}}$hostIndex, $variables, {{/-first}}{{/servers}}$contentType{{/exts.x-group-parameters}}{{#exts.x-group-parameters}}$associative_array{{/exts.x-group-parameters}})
             ->then(
                 function ($response) {
                     return $response[0];
@@ -457,10 +457,10 @@ use {{invokerPackage}}\ObjectSerializer;
      * {{.}}
      *
 {{/description}}
-{{#vendorExtensions.x-group-parameters}}
+{{#exts.x-group-parameters}}
      * Note: the input parameter is an associative array with the keys listed as the parameter name below
      *
-{{/vendorExtensions.x-group-parameters}}
+{{/exts.x-group-parameters}}
 {{#servers}}
 {{#-first}}
      * This operation contains host(s) defined in the OpenAPI spec. Use 'hostIndex' to select the host.
@@ -482,7 +482,7 @@ use {{invokerPackage}}\ObjectSerializer;
 {{/-last}}
 {{/servers}}
 {{#allParams}}
-     * @param  {{{dataType}}}{{^required}}|null{{/required}} ${{paramName}}{{#description}} {{.}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
+     * @param  {{{dataType}}}{{#notRequiredOrIsNullable}}|null{{/notRequiredOrIsNullable}} ${{paramName}}{{#description}} {{.}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
 {{/allParams}}
 {{#servers}}
 {{#-first}}
@@ -499,9 +499,9 @@ use {{invokerPackage}}\ObjectSerializer;
     {{/isDeprecated}}
      */
     public function {{operationId}}AsyncWithHttpInfo(
-    {{^vendorExtensions.x-group-parameters}}
+    {{^exts.x-group-parameters}}
     {{#allParams}}
-        {{vendorExtensions.x-php-param-type}} ${{paramName}}{{^required}} = {{#defaultValue}}{{{.}}}{{/defaultValue}}{{^defaultValue}}null{{/defaultValue}}{{/required}},
+        {{exts.x-php-param-type}} ${{paramName}}{{^required}} = {{#defaultValue}}{{{.}}}{{/defaultValue}}{{^defaultValue}}null{{/defaultValue}}{{/required}},
     {{/allParams}}
     {{#servers}}
     {{#-first}}
@@ -510,14 +510,14 @@ use {{invokerPackage}}\ObjectSerializer;
     {{/-first}}
     {{/servers}}
         string $contentType = self::contentTypes['{{{operationId}}}'][0]
-    {{/vendorExtensions.x-group-parameters}}
-    {{#vendorExtensions.x-group-parameters}}
+    {{/exts.x-group-parameters}}
+    {{#exts.x-group-parameters}}
         array $associative_array
-    {{/vendorExtensions.x-group-parameters}}
+    {{/exts.x-group-parameters}}
     ): PromiseInterface
     {
         $returnType = '{{{returnType}}}';
-        $request = $this->{{operationId}}Request({{^vendorExtensions.x-group-parameters}}{{#allParams}}${{paramName}}, {{/allParams}}{{#servers}}{{#-first}}$hostIndex, $variables, {{/-first}}{{/servers}}$contentType{{/vendorExtensions.x-group-parameters}}{{#vendorExtensions.x-group-parameters}}$associative_array{{/vendorExtensions.x-group-parameters}});
+        $request = $this->{{operationId}}Request({{^exts.x-group-parameters}}{{#allParams}}${{paramName}}, {{/allParams}}{{#servers}}{{#-first}}$hostIndex, $variables, {{/-first}}{{/servers}}$contentType{{/exts.x-group-parameters}}{{#exts.x-group-parameters}}$associative_array{{/exts.x-group-parameters}});
 
         return $this->client
             ->sendAsync($request, $this->createHttpClientOption())
@@ -563,10 +563,10 @@ use {{invokerPackage}}\ObjectSerializer;
     /**
      * Create request for operation '{{{operationId}}}'
      *
-{{#vendorExtensions.x-group-parameters}}
+{{#exts.x-group-parameters}}
      * Note: the input parameter is an associative array with the keys listed as the parameter name below
      *
-{{/vendorExtensions.x-group-parameters}}
+{{/exts.x-group-parameters}}
 {{#servers}}
 {{#-first}}
     * This operation contains host(s) defined in the OpenAPI spec. Use 'hostIndex' to select the host.
@@ -588,7 +588,7 @@ use {{invokerPackage}}\ObjectSerializer;
 {{/-last}}
 {{/servers}}
 {{#allParams}}
-     * @param  {{{dataType}}}{{^required}}|null{{/required}} ${{paramName}}{{#description}} {{.}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
+     * @param  {{{dataType}}}{{#notRequiredOrIsNullable}}|null{{/notRequiredOrIsNullable}} ${{paramName}}{{#description}} {{.}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
 {{/allParams}}
 {{#servers}}
 {{#-first}}
@@ -605,9 +605,9 @@ use {{invokerPackage}}\ObjectSerializer;
     {{/isDeprecated}}
      */
     public function {{operationId}}Request(
-    {{^vendorExtensions.x-group-parameters}}
+    {{^exts.x-group-parameters}}
     {{#allParams}}
-        {{vendorExtensions.x-php-param-type}} ${{paramName}}{{^required}} = {{#defaultValue}}{{{.}}}{{/defaultValue}}{{^defaultValue}}null{{/defaultValue}}{{/required}},
+        {{exts.x-php-param-type}} ${{paramName}}{{^required}} = {{#defaultValue}}{{{.}}}{{/defaultValue}}{{^defaultValue}}null{{/defaultValue}}{{/required}},
     {{/allParams}}
     {{#servers}}
     {{#-first}}
@@ -616,13 +616,13 @@ use {{invokerPackage}}\ObjectSerializer;
     {{/-first}}
     {{/servers}}
         string $contentType = self::contentTypes['{{{operationId}}}'][0]
-    {{/vendorExtensions.x-group-parameters}}
-    {{#vendorExtensions.x-group-parameters}}
+    {{/exts.x-group-parameters}}
+    {{#exts.x-group-parameters}}
         array $associative_array
-    {{/vendorExtensions.x-group-parameters}}
+    {{/exts.x-group-parameters}}
     ): Request
     {
-        {{#vendorExtensions.x-group-parameters}}
+        {{#exts.x-group-parameters}}
         // unbox the parameters from the associative array
 {{#allParams}}
         ${{paramName}} = array_key_exists('{{paramName}}', $associative_array) ? $associative_array['{{paramName}}'] : {{{defaultValue}}}{{^defaultValue}}null{{/defaultValue}};
@@ -631,7 +631,7 @@ use {{invokerPackage}}\ObjectSerializer;
         $variables = array_key_exists('variables', $associative_array) ? $associative_array['variables'] : [];
 {{/servers.0}}
         $contentType = $associative_array['contentType'] ?? self::contentTypes['{{{operationId}}}'][0];
-        {{/vendorExtensions.x-group-parameters}}{{#allParams}}
+        {{/exts.x-group-parameters}}{{#allParams}}
         {{#required}}
         // verify the required parameter '{{paramName}}' is set
         if (${{paramName}} === null || (is_array(${{paramName}}) && count(${{paramName}}) === 0)) {
diff --git a/modules/openapi-generator/src/main/resources/php-nextgen/api_doc.mustache b/modules/openapi-generator/src/main/resources/php-nextgen/api_doc.mustache
index 539b91cc7fff..af99e07c192b 100644
--- a/modules/openapi-generator/src/main/resources/php-nextgen/api_doc.mustache
+++ b/modules/openapi-generator/src/main/resources/php-nextgen/api_doc.mustache
@@ -47,14 +47,14 @@ $apiInstance = new {{invokerPackage}}\Api\{{classname}}(
     new GuzzleHttp\Client(){{#hasAuthMethods}},
     $config{{/hasAuthMethods}}
 );
-{{^vendorExtensions.x-group-parameters}}
+{{^exts.x-group-parameters}}
 {{#allParams}}${{paramName}} = {{{example}}}; // {{{dataType}}}{{#description}} | {{{.}}}{{/description}}
 {{/allParams}}{{#servers}}{{#-first}}
 $hostIndex = 0;
 $variables = [{{#variables}}
     '{{{name}}}' => '{{{default}}}{{^default}}YOUR_VALUE{{/default}}',{{/variables}}
 ];
-{{/-first}}{{/servers}}{{/vendorExtensions.x-group-parameters}}{{#vendorExtensions.x-group-parameters}}
+{{/-first}}{{/servers}}{{/exts.x-group-parameters}}{{#exts.x-group-parameters}}
 $associative_array = [
 {{#allParams}}    '{{paramName}}' => {{{example}}}, // {{{dataType}}}{{#description}} | {{{.}}}{{/description}}
 {{/allParams}}
@@ -64,10 +64,10 @@ $associative_array = [
         '{{{name}}}' => '{{{default}}}{{^default}}YOUR_VALUE{{/default}}',{{/variables}}
     ],
 {{/-first}}{{/servers}}];
-{{/vendorExtensions.x-group-parameters}}
+{{/exts.x-group-parameters}}
 
 try {
-    {{#returnType}}$result = {{/returnType}}$apiInstance->{{{operationId}}}({{^vendorExtensions.x-group-parameters}}{{#allParams}}${{paramName}}{{^-last}}, {{/-last}}{{/allParams}}{{#servers}}{{#-first}}{{#allParams}}{{#-first}}, {{/-first}}{{/allParams}}$hostIndex, $variables{{/-first}}{{/servers}}{{/vendorExtensions.x-group-parameters}}{{#vendorExtensions.x-group-parameters}}$associate_array{{/vendorExtensions.x-group-parameters}});{{#returnType}}
+    {{#returnType}}$result = {{/returnType}}$apiInstance->{{{operationId}}}({{^exts.x-group-parameters}}{{#allParams}}${{paramName}}{{^-last}}, {{/-last}}{{/allParams}}{{#servers}}{{#-first}}{{#allParams}}{{#-first}}, {{/-first}}{{/allParams}}$hostIndex, $variables{{/-first}}{{/servers}}{{/exts.x-group-parameters}}{{#exts.x-group-parameters}}$associate_array{{/exts.x-group-parameters}});{{#returnType}}
     print_r($result);{{/returnType}}
 } catch (Exception $e) {
     echo 'Exception when calling {{classname}}->{{operationId}}: ', $e->getMessage(), PHP_EOL;
@@ -76,10 +76,10 @@ try {
 
 ### Parameters
 
-{{#vendorExtensions.x-group-parameters}}
+{{#exts.x-group-parameters}}
 Note: the input parameter is an associative array with the keys listed as the parameter names below.
 
-{{/vendorExtensions.x-group-parameters}}
+{{/exts.x-group-parameters}}
 {{^allParams}}This endpoint does not need any parameter.{{/allParams}}{{#allParams}}{{#-last}}| Name | Type | Description  | Notes |
 | ------------- | ------------- | ------------- | ------------- |{{/-last}}{{/allParams}}
 {{#allParams}}| **{{paramName}}** | {{#isFile}}**{{{dataType}}}**{{/isFile}}{{#isPrimitiveType}}**{{{dataType}}}**{{/isPrimitiveType}}{{^isPrimitiveType}}{{^isFile}}[**{{{dataType}}}**](../Model/{{baseType}}.md){{/isFile}}{{/isPrimitiveType}}| {{description}} |{{^required}} [optional]{{/required}}{{#defaultValue}} [default to {{.}}]{{/defaultValue}} |
diff --git a/modules/openapi-generator/src/main/resources/php-nextgen/api_test.mustache b/modules/openapi-generator/src/main/resources/php-nextgen/api_test.mustache
index a9aab8044a48..ca88ceb05424 100644
--- a/modules/openapi-generator/src/main/resources/php-nextgen/api_test.mustache
+++ b/modules/openapi-generator/src/main/resources/php-nextgen/api_test.mustache
@@ -68,7 +68,7 @@ use PHPUnit\Framework\TestCase;
      * {{{summary}}}.
      *
      */
-    public function test{{vendorExtensions.x-test-operation-id}}()
+    public function test{{exts.x-test-operation-id}}()
     {
         // TODO: implement
         self::markTestIncomplete('Not implemented');
diff --git a/modules/openapi-generator/src/main/resources/php-nextgen/model_enum.mustache b/modules/openapi-generator/src/main/resources/php-nextgen/model_enum.mustache
index d0a24379e609..cf8b0a7484b1 100644
--- a/modules/openapi-generator/src/main/resources/php-nextgen/model_enum.mustache
+++ b/modules/openapi-generator/src/main/resources/php-nextgen/model_enum.mustache
@@ -1,4 +1,4 @@
-enum {{classname}}: {{vendorExtensions.x-php-enum-type}}
+enum {{classname}}: {{exts.x-php-enum-type}}
 {
     {{#allowableValues}}
     {{#enumVars}}
diff --git a/modules/openapi-generator/src/main/resources/php-nextgen/model_generic.mustache b/modules/openapi-generator/src/main/resources/php-nextgen/model_generic.mustache
index a08517fc7609..73448b8df168 100644
--- a/modules/openapi-generator/src/main/resources/php-nextgen/model_generic.mustache
+++ b/modules/openapi-generator/src/main/resources/php-nextgen/model_generic.mustache
@@ -376,12 +376,12 @@ class {{classname}} {{#parentSchema}}extends {{{parent}}}{{/parentSchema}}{{^par
     /**
      * Gets {{name}}
      *
-     * @return {{{dataType}}}{{^required}}|null{{/required}}
+     * @return {{{dataType}}}{{#notRequiredOrIsNullable}}|null{{/notRequiredOrIsNullable}}
     {{#deprecated}}
      * @deprecated
     {{/deprecated}}
      */
-    public function {{getter}}(): {{vendorExtensions.x-php-prop-type}}
+    public function {{getter}}(): {{exts.x-php-prop-type}}
     {
         return $this->container['{{name}}'];
     }
@@ -389,14 +389,14 @@ class {{classname}} {{#parentSchema}}extends {{{parent}}}{{/parentSchema}}{{^par
     /**
      * Sets {{name}}
      *
-     * @param {{{dataType}}}{{^required}}|null{{/required}} ${{name}}{{#description}} {{{.}}}{{/description}}{{^description}} {{{name}}}{{/description}}
+     * @param {{{dataType}}}{{#notRequiredOrIsNullable}}|null{{/notRequiredOrIsNullable}} ${{name}}{{#description}} {{{.}}}{{/description}}{{^description}} {{{name}}}{{/description}}
      *
      * @return $this
     {{#deprecated}}
      * @deprecated
     {{/deprecated}}
      */
-    public function {{setter}}({{vendorExtensions.x-php-prop-type}} ${{name}}): static
+    public function {{setter}}({{exts.x-php-prop-type}} ${{name}}): static
     {
         {{#isNullable}}
         if (is_null(${{name}})) {
diff --git a/modules/openapi-generator/src/main/resources/php/api.mustache b/modules/openapi-generator/src/main/resources/php/api.mustache
index 8c3377c45c17..ccae14d1424b 100644
--- a/modules/openapi-generator/src/main/resources/php/api.mustache
+++ b/modules/openapi-generator/src/main/resources/php/api.mustache
@@ -156,7 +156,7 @@ use {{invokerPackage}}\ObjectSerializer;
 {{/-last}}
 {{/servers}}
 {{#allParams}}
-     * @param  {{{dataType}}}{{^required}}|null{{/required}} ${{paramName}}{{#description}} {{.}}{{/description}}{{^description}} {{paramName}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
+     * @param  {{{dataType}}}{{#notRequiredOrIsNullable}}|null{{/notRequiredOrIsNullable}} ${{paramName}}{{#description}} {{.}}{{/description}}{{^description}} {{paramName}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
 {{/allParams}}
 {{#servers}}
 {{#-first}}
@@ -215,7 +215,7 @@ use {{invokerPackage}}\ObjectSerializer;
 {{/-last}}
 {{/servers}}
 {{#allParams}}
-     * @param  {{{dataType}}}{{^required}}|null{{/required}} ${{paramName}}{{#description}} {{.}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
+     * @param  {{{dataType}}}{{#notRequiredOrIsNullable}}|null{{/notRequiredOrIsNullable}} ${{paramName}}{{#description}} {{.}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
 {{/allParams}}
 {{#servers}}
 {{#-first}}
@@ -374,7 +374,7 @@ use {{invokerPackage}}\ObjectSerializer;
 {{/-last}}
 {{/servers}}
 {{#allParams}}
-     * @param  {{{dataType}}}{{^required}}|null{{/required}} ${{paramName}}{{#description}} {{.}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
+     * @param  {{{dataType}}}{{#notRequiredOrIsNullable}}|null{{/notRequiredOrIsNullable}} ${{paramName}}{{#description}} {{.}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
 {{/allParams}}
 {{#servers}}
 {{#-first}}
@@ -436,7 +436,7 @@ use {{invokerPackage}}\ObjectSerializer;
 {{/-last}}
 {{/servers}}
 {{#allParams}}
-     * @param  {{{dataType}}}{{^required}}|null{{/required}} ${{paramName}}{{#description}} {{.}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
+     * @param  {{{dataType}}}{{#notRequiredOrIsNullable}}|null{{/notRequiredOrIsNullable}} ${{paramName}}{{#description}} {{.}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
 {{/allParams}}
 {{#servers}}
 {{#-first}}
@@ -526,7 +526,7 @@ use {{invokerPackage}}\ObjectSerializer;
 {{/-last}}
 {{/servers}}
 {{#allParams}}
-     * @param  {{{dataType}}}{{^required}}|null{{/required}} ${{paramName}}{{#description}} {{.}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
+     * @param  {{{dataType}}}{{#notRequiredOrIsNullable}}|null{{/notRequiredOrIsNullable}} ${{paramName}}{{#description}} {{.}}{{/description}} {{#required}}(required){{/required}}{{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{#isDeprecated}} (deprecated){{/isDeprecated}}
 {{/allParams}}
 {{#servers}}
 {{#-first}}
diff --git a/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Api/FakeApi.php b/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Api/FakeApi.php
index 46d603ec1002..5d11eef1670f 100644
--- a/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Api/FakeApi.php
+++ b/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Api/FakeApi.php
@@ -4581,7 +4581,7 @@ public function testAdditionalPropertiesReferenceRequest(
     /**
      * Operation testBodyWithBinary
      *
-     * @param  \SplFileObject $body image to upload (required)
+     * @param  \SplFileObject|null $body image to upload (required)
      * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testBodyWithBinary'] to see the possible values for this operation
      *
      * @throws ApiException on non-2xx response or if the response body is not in the expected format
@@ -4599,7 +4599,7 @@ public function testBodyWithBinary(
     /**
      * Operation testBodyWithBinaryWithHttpInfo
      *
-     * @param  \SplFileObject $body image to upload (required)
+     * @param  \SplFileObject|null $body image to upload (required)
      * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testBodyWithBinary'] to see the possible values for this operation
      *
      * @throws ApiException on non-2xx response or if the response body is not in the expected format
@@ -4648,7 +4648,7 @@ public function testBodyWithBinaryWithHttpInfo(
     /**
      * Operation testBodyWithBinaryAsync
      *
-     * @param  \SplFileObject $body image to upload (required)
+     * @param  \SplFileObject|null $body image to upload (required)
      * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testBodyWithBinary'] to see the possible values for this operation
      *
      * @throws InvalidArgumentException
@@ -4670,7 +4670,7 @@ function ($response) {
     /**
      * Operation testBodyWithBinaryAsyncWithHttpInfo
      *
-     * @param  \SplFileObject $body image to upload (required)
+     * @param  \SplFileObject|null $body image to upload (required)
      * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testBodyWithBinary'] to see the possible values for this operation
      *
      * @throws InvalidArgumentException
@@ -4710,7 +4710,7 @@ function ($exception) {
     /**
      * Create request for operation 'testBodyWithBinary'
      *
-     * @param  \SplFileObject $body image to upload (required)
+     * @param  \SplFileObject|null $body image to upload (required)
      * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testBodyWithBinary'] to see the possible values for this operation
      *
      * @throws InvalidArgumentException
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php
index 5b1bfac6808a..a445ef5ed6e3 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php
@@ -4429,7 +4429,7 @@ public function testAdditionalPropertiesReferenceRequest($request_body, string $
     /**
      * Operation testBodyWithBinary
      *
-     * @param  \SplFileObject $body image to upload (required)
+     * @param  \SplFileObject|null $body image to upload (required)
      * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testBodyWithBinary'] to see the possible values for this operation
      *
      * @throws \OpenAPI\Client\ApiException on non-2xx response or if the response body is not in the expected format
@@ -4444,7 +4444,7 @@ public function testBodyWithBinary($body, string $contentType = self::contentTyp
     /**
      * Operation testBodyWithBinaryWithHttpInfo
      *
-     * @param  \SplFileObject $body image to upload (required)
+     * @param  \SplFileObject|null $body image to upload (required)
      * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testBodyWithBinary'] to see the possible values for this operation
      *
      * @throws \OpenAPI\Client\ApiException on non-2xx response or if the response body is not in the expected format
@@ -4491,7 +4491,7 @@ public function testBodyWithBinaryWithHttpInfo($body, string $contentType = self
     /**
      * Operation testBodyWithBinaryAsync
      *
-     * @param  \SplFileObject $body image to upload (required)
+     * @param  \SplFileObject|null $body image to upload (required)
      * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testBodyWithBinary'] to see the possible values for this operation
      *
      * @throws \InvalidArgumentException
@@ -4510,7 +4510,7 @@ function ($response) {
     /**
      * Operation testBodyWithBinaryAsyncWithHttpInfo
      *
-     * @param  \SplFileObject $body image to upload (required)
+     * @param  \SplFileObject|null $body image to upload (required)
      * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testBodyWithBinary'] to see the possible values for this operation
      *
      * @throws \InvalidArgumentException
@@ -4547,7 +4547,7 @@ function ($exception) {
     /**
      * Create request for operation 'testBodyWithBinary'
      *
-     * @param  \SplFileObject $body image to upload (required)
+     * @param  \SplFileObject|null $body image to upload (required)
      * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testBodyWithBinary'] to see the possible values for this operation
      *
      * @throws \InvalidArgumentException