I had a 2011 Supercrew
You can mount two NMO mounts dead center (on the left/right plane). One can go at the first "cross rib" from the rear of the cab. The second one can go forward of the rear brake light.
If you need to mount 3 or more, you'll need to put some off to the sides.
Going down the dead center, you can drill the 3/4 mounting holes in the center, then route the coaxial cable back towards the rear dome light. You'll need to remove the dome light, but there's a hole just forward of the light where you can route the coaxial cable out. You can route the cable out to the sides and down the back of the cab, or down the "B" pillar if it's a crew cab. On mine, I ran everything to the back drivers side corner and down to the RF decks mounted behind the back seat.
If you are going off to the sides, I haven't done that on an F-150, but I've done it on a 2017 regular cab F-350.
It's a good idea to pull the rubber trim around from the edge of the door and lower the head liner a bit. You don't need to drop it all the way, but enough to see where any cross braces are.
Since you didn't mention which cab style you have, it's hard to guess, but that should get you started.