I'm trying to implement Apple Login using OAuth through the following URL: https://appleid.apple.com/auth/authorize I use the client_id parameter, which corresponds to the Service ID created under Identifiers in the Apple Developer portal. The problem is: an existing Service ID works fine, but when I create a new Service ID and try to use it, I get an invalid_client error as soon as the authorization window opens. I've double-checked everything, but I can't figure out what the issue is. Has anyone else experienced this or knows the cause? Any help would be greatly appreciated!