That's the one I used too. Note that Amazon now says that horn "does not fit RAV4 2021 Prime", but it's complete BS, since it's working perfectly on mine.

Ironically, Amazon now tries to steer me to a horn that advertises 300dB. For context, a nuclear bomb measured from 250 feet away is 210 dB. If that horn was actually 300dB it would definitely kill you and destroy the car. It would likely also be tearing apart the fabric of reality.

But setting aside their lies about volume, the connector on the horn isn't even close to matching the Toyota wiring harness, yet Amazon says "This fits 2021 Toyota RAV4 Prime". Presumably, that's because the manufacturer claims "universal fit". Sure, if you are willing to cut wires and figure out how to bolt it on to the car yourself I guess.