As outlined here, there are a couple of situations where you need to authenticate with GitHub by using an Acces Token:-
- If you have Two-Factor Authentication (2FA) enabled.
- You are accessing an organisations protected content using SAML Single-Sign On (SSO).
In your GitHub account, go to Settings / Developer settings / Personal access tokens
and select Generate New Token
. Make a note of the token somewhere safe since this is the only chance you get to see it.