Change enter and backspace assignment?

Is there a way to change the enter and back key binding in the main UI?
I have an I-PAC keyboard encoder which I can’t change the keybindings.
My player 1 start button currently is associated with num1, and I want that to be the enter key instead.

Go to settings > input and enable “unified menu controls”. That will make your menu navigation use the retropad buttons instead of the hardcoded enter/backspace (that is, the behavior we used to have by default).