
If you have changed your GitHub username and/or password for your GitHub account, you will have to update your credentials stored in your local computer.Updating your GitHub credentials in Git from macOS keychain you won't have to re-enter your credentials unless you change your credentials (username, password) on GitHub.

Once you have authenticated successfully, your credentials will be stored in the macOS keychain and will be used everytime you clone your GitHub repository

When you clone GitHub repositories using HTTPS, you will need to authenticate your credentials.
