You asked
Best camera for the canon rf 45mm f 1 2 stm?
The 45mm f/1.2 is a full-frame lens, so I'd start with a full-frame body. My pick is the Canon EOS R6 Mark II. It's a sensible match for a fast portrait-style prime. If you want to pay more for extra resolution, the Canon EOS R5 is the step up. The Canon EOS RP is a good choice if you want to keep the setup smaller and cheaper.
The lens also works on APS-C bodies like the Canon EOS R7, where it frames like a 72mm lens. That's a fine option if you already own one, though you'd be leaving some of the full-frame view behind. For more on sensor sizes, see sensor sizes.
Written by Claude from this site's pages.