Commodore 64 Competition Pro joystick

[it's me here]

Hi there

Have a functioning Commodore 64 Competition Pro joystick with a Retronic Design USB adaptor.
Joystick mapper sees the joystick, but no matter how I try to map it (and to be honesty I'm not clear on the procedure), or the other examples I look at to try and copy, it doesn't work.

Is anyone able to provide some insight on how to set the joystick up and get it working?

Cheers