Here’s my thread looking into the same thing. You have screenshots of the input and gamepad files, as well as the code you need to print what the gamepad gives you. Try setting it up exactly like that and seeing if it works.
The other option (which I think might actually be better) is to try the following in your on_input function and seeing if you are getting raw data.
if action_id == hash("raw") then
pprint(action.gamepad_buttons)
pprint(action.gamepad_axis)
pprint(action.gamepad_hats)
end