fatal: Authentication fails for git repo 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: git authentication failed

Try below solution which works for me:

1: go to Windows Credential Manager. This is done in a EN-US Windows by pressing the Windows Key and typing 'credential'. In other localized Windows variants you need to use the localized term (See comments for some examples).

alternatively you can use the shortcut control /name Microsoft.CredentialManager in the run dialog (WIN+R)

2: Edit the git entry under Windows Credentials, replacing old password with the new one