Snapdragon (dragon flight) distance sensor to hovering

I brinb up ultrasonic sensor to use downface distance sensor.
And I check about whether PX4 recieve distance sensor data by ORB.
-> I check that distance sensor data recieving is ok at orb_copy(ORB_ID(distance_sensor), _range_finder_sub, &range_finder); / task_main function / EKF2.cpp.

However, when I control dragon flight drone by using Dronecoller apk, I do not know how to make sure that the downface distance sensor works well.
I want to see hovering that the drone is stationary flying at the same height.

So, How can I control drone control apk to see hovering?

I do below action. but I can not see hovering .
First, Mode set ALTCTL Mode, not Manual. at dronecontroller APK .
Sencond, Drone fly in air ( arming -> throttle up )
Third, I take my hand off Joystick of DroneController APK. all parameter( roll, pitch, yaw, throttle) is setted zero.

So I expect Dron is hovering at same height. But hovering is not happened.

please, guide me, how can I control drone to hovering by DroneConroller APK.

I see a similar post below with a reply

I am curious about where I can find the DroneController APK. I’ve checked all the downloads from intrinsync and only find invalid or outdated references to it.