Using the debug port of the pixhawk for a sonar

Hello there !

I am a begginer using pixhawk and I would like to if I can use the debug port of the pixhawk to use a ping sonar by bluerov and if yes how do I set it as a rangefinder in mission Planner.

This is probably obvious but I must ask because my other serie ports are already used for other telemetry sensors.

I apologies in advance for my mistakes in english.

Thanks !