When my PHP callback receives a file access event from Google Drive, my server returns a 403 error. It turns out that the problem is due to JSON data embedded in the GET parameters, which the server cannot process correctly. I am exploring whether there is a way to modify the redirection so that Google Drive sends the data using POST parameters instead, potentially resolving this issue.
Based on my experience when dealing with similar issues, determining the use of POST parameters during a redirect isn’t straightforward because HTTP redirection mechanisms naturally stick with GET when the client is redirected. It may be more effective to manage the redirection on your own by setting up an intermediate endpoint that captures the GET data and then submits it via POST to your callback endpoint. This approach allows you to handle the incoming JSON data more gracefully, avoiding the 403 error by effectively transforming the request method.