diff --git a/api_names_out.yaml b/api_names_out.yaml
index 88c83e32632..1bd5da8a611 100644
--- a/api_names_out.yaml
+++ b/api_names_out.yaml
@@ -247874,6 +247874,7 @@
 "/firebaseappdistribution:v1alpha/firebaseappdistribution.projects.apps.testCases.list/pageToken": page_token
 "/firebaseappdistribution:v1alpha/firebaseappdistribution.projects.apps.testCases.list/parent": parent
 "/firebaseappdistribution:v1alpha/firebaseappdistribution.projects.apps.testCases.patch": patch_project_app_test_case
+"/firebaseappdistribution:v1alpha/firebaseappdistribution.projects.apps.testCases.patch/allowMissing": allow_missing
 "/firebaseappdistribution:v1alpha/firebaseappdistribution.projects.apps.testCases.patch/name": name
 "/firebaseappdistribution:v1alpha/firebaseappdistribution.projects.apps.updateTestConfig": update_project_app_test_config
 "/firebaseappdistribution:v1alpha/firebaseappdistribution.projects.apps.updateTestConfig/name": name
diff --git a/generated/google-apis-firebaseappdistribution_v1alpha/CHANGELOG.md b/generated/google-apis-firebaseappdistribution_v1alpha/CHANGELOG.md
index 9a503a86be3..70fe018e373 100644
--- a/generated/google-apis-firebaseappdistribution_v1alpha/CHANGELOG.md
+++ b/generated/google-apis-firebaseappdistribution_v1alpha/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Release history for google-apis-firebaseappdistribution_v1alpha
 
+### v0.19.0 (2025-09-21)
+
+* Regenerated from discovery document revision 20250916
+
 ### v0.18.0 (2025-09-14)
 
 * Regenerated from discovery document revision 20250912
diff --git a/generated/google-apis-firebaseappdistribution_v1alpha/lib/google/apis/firebaseappdistribution_v1alpha/gem_version.rb b/generated/google-apis-firebaseappdistribution_v1alpha/lib/google/apis/firebaseappdistribution_v1alpha/gem_version.rb
index 31d5601adaf..3c6d4fb6332 100644
--- a/generated/google-apis-firebaseappdistribution_v1alpha/lib/google/apis/firebaseappdistribution_v1alpha/gem_version.rb
+++ b/generated/google-apis-firebaseappdistribution_v1alpha/lib/google/apis/firebaseappdistribution_v1alpha/gem_version.rb
@@ -16,13 +16,13 @@ module Google
   module Apis
     module FirebaseappdistributionV1alpha
       # Version of the google-apis-firebaseappdistribution_v1alpha gem
-      GEM_VERSION = "0.18.0"
+      GEM_VERSION = "0.19.0"
 
       # Version of the code generator used to generate this client
       GENERATOR_VERSION = "0.18.0"
 
       # Revision of the discovery document this client was generated from
-      REVISION = "20250912"
+      REVISION = "20250916"
     end
   end
 end
diff --git a/generated/google-apis-firebaseappdistribution_v1alpha/lib/google/apis/firebaseappdistribution_v1alpha/service.rb b/generated/google-apis-firebaseappdistribution_v1alpha/lib/google/apis/firebaseappdistribution_v1alpha/service.rb
index a45c84a5c97..92e2714d5e1 100644
--- a/generated/google-apis-firebaseappdistribution_v1alpha/lib/google/apis/firebaseappdistribution_v1alpha/service.rb
+++ b/generated/google-apis-firebaseappdistribution_v1alpha/lib/google/apis/firebaseappdistribution_v1alpha/service.rb
@@ -724,6 +724,9 @@ def list_project_app_test_cases(parent, page_size: nil, page_token: nil, fields:
         #   Identifier. The name of the test case resource. Format: `projects/`
         #   project_number`/apps/`app_id`/testCases/`test_case_id``
         # @param [Google::Apis::FirebaseappdistributionV1alpha::GoogleFirebaseAppdistroV1alphaTestCase] google_firebase_appdistro_v1alpha_test_case_object
+        # @param [Boolean] allow_missing
+        #   Optional. If set to true, and the test case is not found, a new test case will
+        #   be created.
         # @param [String] fields
         #   Selector specifying which fields to include in a partial response.
         # @param [String] quota_user
@@ -741,13 +744,14 @@ def list_project_app_test_cases(parent, page_size: nil, page_token: nil, fields:
         # @raise [Google::Apis::ServerError] An error occurred on the server and the request can be retried
         # @raise [Google::Apis::ClientError] The request is invalid and should not be retried without modification
         # @raise [Google::Apis::AuthorizationError] Authorization is required
-        def patch_project_app_test_case(name, google_firebase_appdistro_v1alpha_test_case_object = nil, fields: nil, quota_user: nil, options: nil, &block)
+        def patch_project_app_test_case(name, google_firebase_appdistro_v1alpha_test_case_object = nil, allow_missing: nil, fields: nil, quota_user: nil, options: nil, &block)
           command = make_simple_command(:patch, 'v1alpha/{+name}', options)
           command.request_representation = Google::Apis::FirebaseappdistributionV1alpha::GoogleFirebaseAppdistroV1alphaTestCase::Representation
           command.request_object = google_firebase_appdistro_v1alpha_test_case_object
           command.response_representation = Google::Apis::FirebaseappdistributionV1alpha::GoogleFirebaseAppdistroV1alphaTestCase::Representation
           command.response_class = Google::Apis::FirebaseappdistributionV1alpha::GoogleFirebaseAppdistroV1alphaTestCase
           command.params['name'] = name unless name.nil?
+          command.query['allowMissing'] = allow_missing unless allow_missing.nil?
           command.query['fields'] = fields unless fields.nil?
           command.query['quotaUser'] = quota_user unless quota_user.nil?
           execute_or_queue_command(command, &block)