It uses the old binding system, go to Vehicles in the binding list and scroll to the bottom. There you should see "E-Function", "F-Function", etc. Map the buttons shown in the overview to their corresponding Function and you should be good to go.
whoops i didnt try the controls yet. my arrows keys on my laptop dont work so i wouldnt be able to anyway.
̶T̶h̶e̶ ̶s̶i̶m̶p̶l̶e̶,̶ ̶f̶a̶s̶t̶,̶ ̶a̶n̶d̶ ̶s̶a̶f̶e̶ ̶w̶a̶y̶ ̶o̶f̶ ̶t̶r̶a̶v̶e̶l̶l̶i̶n̶g̶ ̶i̶n̶ ̶t̶h̶e̶ ̶f̶u̶t̶u̶r̶e̶.̶ The tough, slow (more than 24 hours are spent to identify the issue) and (emotionally) harmful way of travelling in the past. Now it's slogan sounds so ironic. (In fact it works perfectly. This joke is about the old bindings system only.) --- Post updated --- P-key doesn't present in the current version of the game.
P-key doesn't present in the current version of the game. Nah. No effect. At first I had the same assumption.
It's the parking brake and it does have an effect. Test it on the infinite flat map, go forward as fast as you can, then reset, press the P button and try it again, the altitude will be locked. Hard to notice on normal maps but it works, the effect is not so big.
That was before the last update which must have broken it I guess, I don't use this mod anyway and it took me a few minutes to fix so I didn't really care about it, I can check later if it works for me