Bleeding brakes from 2012 Prius with pneumatic bleeder

You don't need this.
Brake bleeding is done by the Prius itself. It re-pressurizes the system with a slight pressure leak.

 

I’ve done a couple of brake fluid replacements so far, using the non-Techstream method (proscribed in Repair Manual). My tools were very rudimentary, no external vacuum used, apart from a baster to initially extract/replace reservoir fluid.

when doing brakes, specifically when retracting caliper pistons for new pads, I’ve never opened bleed screws, and never had subsequent problems. Brake fluid replacement is worthwhile, but I would leave it for another day, and be careful to do it by the book.

there’s links in my signature, one for brake fluid change, the other about rear brake drag; both have relevant info. (On a phone turn it landscape to see signatures).