[SOLVED] Problem authorizing with Home Connect (Bosch cloud api)

I’m trying to get my Bosch dishwasher to work with HA. I have tried to follow to instructions on Home Connect - Home Assistant to setup a developer application, but my client credential does not seem to be accepted. When I am trying to add the actual “Home Connect” integration in HA, all I get is this response from api.home-connect.com:

  "error": "unauthorized_client",
  "error_description": "client or redirection URI not authorized",
  "state": "..."

I’ve tried specifying client credentials using both the GUI way and hard-coded in configuration.yaml. I’ve tried creating two different applications. I’m getting kind of stuck now.

Do anyone have any suggestions on how to figure out the problem?

Solved. The issue was that the documentation is incorrect, you must specify an externally reachable URL.

I’ve filed a bug on the documentation: https://github.com/home-assistant/home-assistant.io/issues/24017

Still can’t get it to work. If I enter the callback as follows, but when I try this manually I get a 404, which means the address can be found but the redirect/oauth portion not. What am I doing wrong. This has to be the worst documented integration…

https://my external address/redirect/oauth