I think by default boost is circle (PlayStation) and B (xbox) and jump is x (PlayStation) and A (xbox). I believe roll/slide is mapped to square (PlayStation) and x (xbox). I changed boost to square/x and the roll button to l1/lb. I kept jump the same. It makes it much easier to jump/boost/roll/accelerate all at the same time.

I still have jump on ps:x or Xbox:a, and mapped boost to rb/r1. Then drift and air roll on lb/l1