Problem in assembly (front wheel steering)

When I setup a VTAIL plane(software VTAIL mixer),RC2 and RC4 channel should be added to v-tail Steering engines. but which channel should be added to the Front wheel Steering engine ?
can anybody help me?

I would set up an extra output using the “Rudder” or even better “Groundsteering” function and attach the nosewheel to that. You can also reverse it if needed there.

plane.ardupilot.com/wiki/flight- … ns/#rudder