After Aug 13, it looks github.com stopped password based authentication completely and it expected personal access token for all the github activities.
Here I will show you how to create a personal access token to perform github operations like pull, commit, push etc.
Step 1: Go to Settings
Step 2: Settings -> Developer settings
Step 3: Navigate to personal access token
Please copy paste the token somewhere you will be able to see the token only once.
Now access or perform all github related stuffs with the token generated.
Username remains same and instead of entering the passwords start entering/pasting the token generated in the above steps.