I’ve transported a couple of bikes in the back fo my Dad’s Frontier. You’ll probably need to drop the gate. Three tie downs and three guys are all you need.
A 2×6 works for a ramp in a pinch. Failing that, ramps are available (around here anyways) for $50-$75. That said, three guys can lift a 400 pound (dry) bike without any ramp (done it).
If it has old-school dual mufflers (“bazooka mufflers” like the older Ninja 250), two guys lift the handlebars onto the bed, and a third guy in the bed holds them steady. The other two then lift the bike from where the mufflers attach to the bike (seriously, just lift them by the mufflers, they were built for it).
not sure how you’d lift a newer single sided muffler bike – ask a the service guys at a dealership, they’ll be pretty experienced with it.
When you tie it down,place the front wheel against the front wall, hook both tie downs to the top of the fork (right under or on where the handlebars attach) and crank those ties down. You want the front fork as compressed as possible. Once that is done, Bob’s your uncle, it isn’t going anywhere. I then put a strap through the back wheel for at extra bit of safety.
if at all possible back the truck towards a hill so the bike ramp, or distance lifted is as close to level as possible.
“The two seconds between ‘Oh S**!’ and the crash isn’t a lot of practice time.”