remote: Support for password authentication was removed on August 13, 2021.

remote: Please see https://docs.github.com/get-started/getting-started-with-git/about-remote-repositories#cloning-with-https-urls for information on currently recommended modes of authentication.
fatal: Authentication failed for 'https://github.com/myrepo/app.git/'

Solution: use gh auth login to authenticate to repo

git config user.name
git push

See also

• git config, .git/config, ~/.gitconfig, --list, --global, Usage: git config, credential.helper