PWM or servo output cube purple


I’m trying to get my head around my cube purple, fitted on a mini carrier board. but can’t see the wood for the trees.

I’m using a mateksys elrs 2.4 D reciever to communicate between my radio master TX16S

That works ok and can see the servos move in mission planner. When I have the cube connected via USB or via holy bro telemetry radios.

I’m also using holybro telemetry radios so I can control my craft via Mavlink via an autopilot app on a tablet.

I’m trying to control a twin motor boat. So have mission planner on Rover.

Have worked out how to set up steering etc etc

But cannot get any output signal from the cube purple to the motors or servos.

And can’t understand any of the technical stuff I’m reading on elrs to PWM

I don’t want to be buying another elrs recover to PwM with 5 channels.

As I may as well bin the cube if I have to do that.

How do I get the cube to tell the motors when to run and how fast etc? Or any of the other servo outs so the solenoids etc I have work?

I’ve tried arming etc but nothing.

Help please.