how to create domain proxy for psiphon?

hello everyone
Before I ask my questions, I apologize for my bad English language - this is because i'm from 3rd world country and my English language is very weak and write this text using google translate.

I have been familiar with free internet (simcard freenet) forums for about 4 years that most of these forums are usually from the Philippines or Brazil - Freenet forums usually provide config for free internet like http injector config (.ehi config) and proxy host for psiphon settings - sometimes this forums provide public websites with 80 port that we most set in psiphon proxy settings to get free internet for simcard - now i want to know how a website can working like proxy with port 80 if no proxy source is running on it? - are there any tutorials to convert a cpanel host and connected domain to http proxy without running any proxy source on it? (using 80 port for using in psiphon proxy settings)