The redirect URI in the request, http://www.regenbogenwiese.net/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/852782912189-kmo71eogf8utpqb458bej8jh2sa36umu.apps.googleusercontent.com?project=852782912189