The redirect URI in the request, https://schachtraining.chessbase.com/oauth2callback, 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/98275370805-dougjfhctv5o342bm85mtvrskv6kolv7.apps.googleusercontent.com?project=98275370805