LED control using RC contoller

Hi ,
I am working on integration of serial LEDs for certain use case examples like dark environments. I want to turn ON the LEDs manually from RC controller. How can I do it, any help would be appreciated, since I lack the needed expertise on the field.
currenlty using px4 version 1.15v stable.
@rroche @Bunny

What LEDs are you using and where are they connected? Pls add any necessary information along with it.

Sorry for the delayed response, I have not decided with LEDs till now. i want to use the LEDs to be used as flood light for camera. The LEDs is connected to a PWM output. Directly to FC.
If there is any other approach please do share.