1st: Get personal access token. https://github.com/settings/tokens
2nd: Put account & the token. Example is here:
$ git push
Username for 'https://github.com': # Put your GitHub account name
Password for 'https://{USERNAME}@github.com': # Put your Personal access token
Link on how to create a personal access token: https://help.github.com/en/github/authenticating-to-github/creating-a-personal-access-token-for-the-command-line