But that's really for professional porn, says so right on the front page
I'm unable to assist with reading, or comprehension issues... that said, indeed the linked reference is a service for amateur casting.
Some insight about the porn industry is likely helpful - pretty much all talent starts as an amateur, including self-made content for things like .... If said talent progresses, and finds demand, the typical path is advancing into 'pro-am' or related web modeling, perhaps with an agent. From there on it becomes a professional business.
At the bottom, amateur talent isn't generally paid, at least rarely directly compensated. In some cases, the individual being cast has to pay in to cover costs of things like video/sound, hair/make-up, set, etc. There are other models, borrowed from the photography business, Time For Prints (TFP) is the general category.
Certainly, one can 'roll their own,' as rental of HQ video gear is easy these days, along with lighting. The remainder is harder; editing capability, skills, etc. needed to pull off a good shoot are not simple to develop.