gitpython: How to authenticate as a Github app?

When I do

remote = f"https://{username}:{password}@github.com/user/repo"
git.Repo.clone_from(remote, 'repo')

I get to clone the repository with my personal credentials.

But if I try an app credentials

remote = f"https://x-access-token:{token}@github.com/user/repo.git"
git.Repo.clone_from(remote, 'repo')

I get

remote: Invalid username or password. fatal: Authentication failed for 'https://github.com/user/repo'

I have installed the app and added it to the repository integrations. It has content permissions to read and write.

I am using the client secret as the token.