Any J2534 dongle ought to work. The $500 DrewTech one is the one Toyota officially tests with and cares about if you have trouble with it. I think you will find far more people on PriusChat who have spent $40 or less on their J2534 dongles than you'll find who have spent $495. There are products available across the whole price range between. Build quality is the main differentiator. The ones at the low end in theory work just as well, but in practice not always. They're great when they do, and frustrating when they flake out.
The low end ones as far as I've seen leave one (or more) wire(s) out that connected allows programming/flashing ECUs. That said I only used the flash feature once. (It's up to you whether it is worth it to you. Actually the flash was covered under an extended warranty/TSB so it could have been free at a dealer had evidence of the issue not been erased). REVVL V+ 5G ?
I've, so far, always gone to the dealer when I wanted any reflashing done. It's worth it to me to pay them for the higher-quality dongle they will use, and to let it be their problem if anything in the reflash goes wrong and bricks my car.
