Fail to merge PR in other repository in the organization with App Token

I’m trying to merge PRs from different repositories of the same organization from GitHub Action with GitHub App Token.
However, this fails with an error message “Resource not accessible by integration”.
As for the permissions, the app can read and write the contents and pull-request.

Are there any restrictions on the use of GitHub App Token within an organization?
Or do I need to do some additional configuration in the repository where the merge will take place?

I have already tried the following:

  • Succeeds if PAT is used instead of App Token
  • Referencing an issue in the target repository from the same GitHub Action succeed

Not that I solved it, but
I was able to merge the PR by using PyGitHub instead of trying to merge using gh pr merge.

Is it because PyGitHub uses restapi, while the gh command uses graphql?
I think there is a bug.