Substrate Eye? Examples of the maps it needs?

I want to make a fish eye using substrate eye bsdf, and it takes a whole bunch of inputs I can’t quite sort out what they actually need. I also cant find any examples or explanation of how to use this bsdf? The marketplace content example is listed as “unavailable”, I’d look there but can’t get it.

Anyone know any clues I can try?
image

Well content examples randomly became available again, and … the eye is not so easy to figure out. It also seems to be flickery. Hopefully I can break this down!