Welcome to Ford-Truck Enthusiasts!
Which cab configuration do you have? The controller/module (KEM) is usually on the back wall of the truck. If you have the screw or scab you'll have to remove the rear-seat (the back portion) to find it. There should be a label on it when you find it.
Here was an earlier article on removing the seat:
https://www.ford-trucks.com/article/...2008_F150.html (It also mentions finding the KEM.)