Just to help you out here, the reason you want a true sine wave is because it is “cleaner” in the electronics. Cheap inverters produce a square wave, more expensives produce a modified sine wave and more expensive are True Sine wave inverters.
Imagine a smooth rolling wave on the water, it goes up 3 ft and then back down to level, down 3 ft, back up to level, and so on. That is true sine wave. The 3ft would equal 120volts, the up and down happens 60 times a second.
The square wave is the same, but instead of smooth curves, you get straight lines, so it would go up, over, down, over, up and so on.
A modified square wave is still mostly square, but through some filters, usually capacitors and coils, they round off just the sharp edges of the square wave.
From a distance, far from the beach, they all look about the same, but as you get closer in, you can clearly see the waves shape.
If you were looking at the electrical wave on an oscilloscope, it looks just like that but it’s a green line on a graph instead of water on a beach.
So the more sensitive your electronics are, like computers and such, the more “dirty” inverters wreak havoc.
If you had a modified sine wave inverter for your truck, ok, fine, so buy a small true sine wave inverter that has enough power for your personal electronics.
I am assuming you are a driver, not owner. If I was an owner, I would just buy a good APU with true sine wave.