Kindark

Hi guys! So i installed and android auto apple carplay module in my original navigation. The only problem i have is that when i get the car in reverse (also car is a manual) the backup interface doesn't show up (neither camera nor sensor). After calling the module distributor i was told that for a manual car i will have to tap a 12V wire from the reverse of the car to the module, so the module knows when the car is in reverse. Where would i be able to find a wire close to the central console that activates with a 12V signal when i put the car in reverse so i can tap into it? Any ideeas?