The redirect URI in the request, https://plz-clan.de/index.php?google-auth/, does not match the ones authorized for the OAuth client. To update the authorized redirect URIs, visit: https://console.developers.google.com/apis/credentials/oauthclient/530317232361-ntr45p47ba561o2ffc76racvv614snd1.apps.googleusercontent.com?project=530317232361