github fatal: Authentication failed for code example

Example 1: can't push to github authentication failed

git remote -v 
git remote remove origin 
git remote add origin [email protected]:user/repo.git

Example 2: authentication failed github

Authentication failed.
You may not have permission to access the repository

Stepa to fix issue:

1.Remove repo from GitHub Desktop
2.Logout from your github account [File > Options]
3.File > Add Local Repository
4.Repository > Repository Settings and change to https URL [Important tweek]
5.It started working back for me.