We had the 66th, and the 131st and the Urals at the hayfield ... The Urals are the best! But there is also Tatra, that one also gives heat! Somehow, as a child, I saw how MAZ first got stuck in the mud, came to the rescue of KrAZ, and then to them - a loaded old Tatra with right angles of the nose. So she pulled everyone out in one fell swoop. It was around 64, but this scene still stands before my eyes
Most military vehicles come with chains for ditching and unditching. If the truck starts sliding going up a steep dirt incline you join the rear chains like a track and it will easily clime the hill.
On the first truck, the wheels are not for off-road, but for road driving, narrow with a small tread, and inflated to failure, everything to save on fuel, put the tires wider, with a deep tread and lower them by half, and change the gasket between steering wheel and pedals and everything will be ok
If it doesn't work the first 37 times, just keep doing the same thing. Or... Let some air out of the rock-hard tires, turn the angle of direction just a few degrees, try steering left and right for a bit of different traction or install lockers. Any 1of these, or a combination of them, might surprise you.