Edwin I've killed the instance, deployed the app again, updated the OAuth key again. When I scan the QR code and allow the OAuth connection in the bunq app, I get an error in the python app running in the Google Cloud:
An unknown exception occurred. See the logs.
When I check the logs, this is the result:
2019-07-14T10:21:03.662158Z [bunq] Installing key...
2019-07-14T10:21:03.664079Z POST v1/installation
2019-07-14T10:21:03.950589Z [bunq] Registering token...
2019-07-14T10:21:03.950625Z POST v1/device-server
2019-07-14T10:21:04.546530Z GET v1/user
2019-07-14T10:21:04.679676Z {'Error': [{'error_description': 'The request signature is invalid.', 'error_description_translated': 'The request signature is invalid.'}]}