I already setup SSH for GitHub which tutorial provided from GitHub, but there still somtething error with my Public Key Permission Denied, so that means I have missed the config.
Solution that worked in my case was that I renamed the pub and private key to id_rsa. That solved the cause. Also those who already have files by this name, should try
chmod 600 ~/.ssh/id_rsa* from Git bash, assuming you installed Git for Windows.