We followed the steps in this doc to integrate Apple Social Connection (https://marketplace.auth0.com/integrations/apple-social-connection). When trying to log in with the Apple connection, we received an invalid redirect URL error.
Try a sample /authorize on the Apple connection and notice the expected redirect URI that is being sent and rejected by Apple.
Invalid redirect URI configured on the Apple side, there should be https://MY_AUTH0_DOMAN_NAME/login/callback included.
This error can be caused by an invalid redirect URI on the Apple side and when using the App ID instead of the Services ID from Apple as a client_id. In this case, it was the redirect URI that was incorrect.