You really need to look on the security perspective to harden it. When it's marketed with security in mind. And there's so many things wrong with the PHP synta

You really need to look on the security perspective to harden it. When it's marketed with security in mind. And there's so many things wrong with the PHP syntax etc. as well as you have committed the entire Composer vendor/ folder. Put it in gitignore and remove it. You should not commit dependencies to your code base.