Home Assistant with hangout integration

Hi All,
I am sure, some one can help me again.
I am using HA in docker on Synology. And currently trying to activate the notification via hangouts. However, no matter what I do, it always gives me log in error.
Thanks to this post, I am able to login and also chat in hangups. Even though the session in hangups is active, I am not able to connect this session to home assistant.
Any idea what I am doing wrong …