AC light turns itself off, blows hot

Got a 2017 Prime. Started blowing warmer. Now it's basically got no cooling power at all. I figured maybe I just needed a refrigerant top-up. That led me down a rabbit hole of trying to figure out which refrigerant, and whether I should do it myself, as I have in every other car I've had. Still haven't figured out the answer to either of those. I have a can of R134a.

Anyway. Connected the cheapo gauge with the can, and even though I lost a little refrigerant in the process of just checking, I think, the refrigerant was still in the green. (Can't remember for sure right now, but probably 35 or so?)

Stopped there to do more research. Checked error codes with the button-pushing trick, and got 00. Which means no errors, correct?

But here's where I'm really puzzled: I had the AC and recirc buttons on, just to see if anything would happen. In a few minutes, both the lights were off. Repeated to make sure I wasn't missing something, and yep, for sure. It's done it repeatedly.

When I hit AC, I hear a pretty loud sound which I assume is the compressor.

I just paid a boat load to get my daughter's AC fixed (on a Honda), so if this is doable without trying to find a Prius AC specialist, that sure would be nice.

Any ideas? Thanks!