Controlling a Servo from the Mavic Air Controller

This project was only to see if it will work, and now I see a few possibilities for this.
HOW IT WORKS.
Actually this is very straight forward, on the inner workings of this unit.
I’m using the Mavic Air front Lights to control the Servo
In DJI go 4 App, you can assign funtions to the “C” and “Fn” buttons on the controller
STEP 1:
In the DJI Go 4 App, goto the Remote Controller settings, and assign “Turn on/off head
LED’s” to “Fn” or “C” switches.
STEP 2:
Building the Arduino Unit
What