This is the part that seems to have fixed my broken Folding Seat Latch Release for the rear row in my 2019 Rav4. It is a simple design and probably could be done even easier. The long tab is great for grabbing with tweezers or needle nose pliers also stops it from falling deep into the seat frame.

There is a wire that goes from the latch release handle to a nylon lever. It passes through a hole in the lever and seems to have had a rivet in that hole that broke off.

Removing the plastic cover showed two screws holding the handle assembly in place. Removed those, unhooked, unzipped, and moved the seat cover out of the way, then gently but firmly pulling the handle mechanism out. Then I simply put this part onto the wire and then finagled the piece back down while getting the pla part/wire back into the hole in the nylon lever.