Airspeed Pitot Sensor Parameters not showing up on Mission Planner

I have been trying to connect the airspeed pitot sensor into the Pixhawk 2.1, however, the paramater list does not seem to show on the full parameters list. Anybody encountered this issue?
we are using PX4AIRSPEEDv1.1 airspeed pitot sensor

By the way, we are using Mission Planner 1.3.56

After reading other treads, I found out that we had the wrong firmware. After installing the plane firmware onto the pixhawk 2.1, the arspd parameters showed up.