I am the owner of the repository. I created a test token with ALL permissions and i tried to use OAuth2 API way too.
Sadly have then no idea what is going on there and can sadly also not debug it as I can not reproduce this issue.
Did you try to create a webhook via the API (via HTTP Request Node, curl, or Postman)? Does that work?
https://docs.github.com/en/rest/webhooks/repos?apiVersion=2022-11-28#create-a-repository-webhook
Not yet. I’ll try tomorrow