How to register my iPhone for remote play on my PS3 because I cannot figure it out?

How to register my iPhone for remote play on my PS3 because I can't figure it out? - 1

You don't. Only the PSP can be used, and even that implementation wasn't good. It was up to the games to support it, not the system, so most didn't.

The PS4-Vita remote play is done at the system level, which increases compatibility.

Phones can't use remote play, only the psp and psvita can. To register a psp or psvita you would turn on both, go to settings on the ps3 to register then you'd get a 10 digit code to input into the psvita or psp to register it, you'd also need both to use the same psn account