Fixed PHP error

# Conflicts:
#	CHANGELOG.md

Author: brandonkelly

CHANGELOG.md

@@ -10,6 +10,9 @@
 ### Changed
 - Webhooks now requires Craft 3.7 or later.
 
+### Fixed
+- Fixed an error that could occur when calling `craft\webhooks\Plugin::getRequestData()` if an invalid request ID was passed.
+
 ## 2.3.3 - 2021-04-01
 
 ### Fixed

src/Plugin.php

@@ -338,7 +338,7 @@ public function getRequestData(int $requestId): array
             ->one();
 
         if (!$data) {
-            throw new InvalidArgumentException('Invalid webhook request ID: ' . $this->requestId);
+            throw new InvalidArgumentException('Invalid webhook request ID: ' . $requestId);
         }
 
         if ($data['requestHeaders']) {