The redirect URI in the request, https://esaga.uni-due.de/accounts/google/login/callback/, 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/806866338409-hnlifj2joa10jbh3np85gj8v2c33uevo.apps.googleusercontent.com?project=806866338409