I need to change the controls on xbox controller

I’m playing on PC and I need to be able to change the controls on my xbox controller but I can’t. Why doesn’t this game allow me to do it?

I’m playing on PC and using Xbox controller because using the mouse gives me RSI in my wrist. When I’m riding around on my horse and sprinting (holding down B) I like to be able to look around and enjoy the view (using the right analog toggle), however can’t do this because my right thumb is preoccupied holding down B. If only I could change the controls I would make R1 the sprint button and use it with my left finger which would allow me to look around with my right thumb. This is basic ergonomics really but it would really enhance my enjoy-ability of the game.

Does anyone know how to fix this? If not, please can the devs add this feature?