Ardurover Motor Debuging

Hi, I’m just getting started with learning ardupilot and building a rover.
I’ve used a cytron motor driver and hooked it up as seen here

When I try and test the motors as documented here, i just get atone. No message and the motors dont turn.

I am using my pc connected via radio to send the commands. I arm the rover and get a good tone. I know the motors have power because there is a test button on the cytron motor driver that turns them.

I’m very new to all this and could use some help in how people go about debuging things like this… i’m sure this will be the first of many things to solve!