I purchased 4th gen with only one key. I want to program a duplicate key at home without having to do to dealers and pay arm and leg.
You’ll need a J2534 dongle (like miniVCI and VXDIAG) and Techstream . It can be bought on Amazon . Good luck and keep us posted .
There was a thread about this a couple of years ago, and I thought there was a mention of a locksmith?
Locksmiths are another route, but they won’t be as cheap as the miniVCI setup . I’ve used that successfully to pair a key to a Prius for another member here recently (it was a Gen3). But probably still cheaper than the dealer.