To deploy code you need SSH access to the server on which code is to be deployed. In particular the server need not have any private or deployment keys which give it access to github. The server merely needs to be configure with public keys.
We assume the deployment server is Debian or a derivative like Ubuntu. By convention web-apps are deployed to /var/www/sitename.com. This will work with both Apache & Nginx.
/var/www/sitename.com: