Ethan, if you do not have a web server that runs php code, you can't run whatever that script is.
Do you have a web server? (not just Gmod, but, a address you can type in a web browser, like, we use
www.ulyssesmod.net as our front page...that's our server hosting.)
Does it run PHP code? (PHP is a server side scripting language, sort of like GLua is for Gmod client and server side).