Jenkins could not checkout in in an automatically created pull request

Question

I created a script in Python which automatically creates PR and the repo has Jenkins pipeline enabled.

Unfortunately Jenkins cannot handle PR created from script. Manually created PR is handled without troubles. I have tried changing PR name, branch name, and commit message and nothing helps. I guess it might have something to do with setting credentials by GIT_ASKPASS. I am using PyGithub library. When I am creating PR by hand I use git configuration with Windows Credentials Manager, however when PR is created from script, I pass only GIT token.

from github import Github

repo = Github(base_url=f"https://{HOST}/api/v3").get_repo(REPO_NAME)

### Adding commits and other stuff here ###

repo.create_pull(title=pr_name, body=body_message, head=branch_name, 
                 base="master")

Is it indeed problem with credentials, and if so how it can be handled?