This is on driver's side on the left of the hybrid battery. I've watched a youtube video on a guy taking out the hybrid battery and it's kind of hard to see but it looks like he doesn't have it
That connects to an SKS system receiver. Apparently, the plug is there even if the car isn't equipped with SKS. I think it's labelled as a smart key oscillator Toyo #89992-47040 An older thread from another member What's this thing? | PriusChat
ohh ok weird and ya my key fob is not a smart key. I have to manually press the unlock for it to unlock the door as opposed to my Lexus, where I just reach for the handle and it unlocks. Thank you
The connector is there, just hiding behind the loom in that video. Here is an example of the missing SKS sensor supplied by Tokai-rika :
No intention for you to upgrade built in, just fact that all cars are made from the same wiring harness regardless of features of that particular vehicle.