jump should be x while grapple is c. Its really natural to roll the fingers inward but unnatural outwards. although I wouldn't use x or c in the first place. wasd with k as jump and j as grapple
PICO-8 maps Z and C to the same input (as with X and V) so you could just shift your hand over 1 key and get the same effect, at least on a QWERTY keyboard. Also the mappings are built into PICO-8 itself, so I'm not sure if there's any reasonable way to change them.
Wait you mean this screen? As far as I'm aware it just tells you the inputs and lets you test them. (If you're referring to something else I actually genuinely don't know or see it)
