Answer by iamsurajdc for Remove credentials from Git

For macOS users :

This error appears when you are using multiple Git accounts on the same machine.

Please follow below steps to remove the github.com credentials.

1. Go to Finder
2. Go to Applications
3. Go to Utilities Folder
4. Open Keychain Access

5. Select the github.com and Right click on it

   Delete "github.com"

Try again to Push or Pull to git and it will ask for the credentials. Enter valid credentials for repository account. Done