Parameter for landing gear on fixed wing

what parameters do I need to set so that my landing gear is listening to channel 7 on my Radio?
Until now I’ve tried following parameters:
Changed RC_GEAR_TH from 0.25 to 0.5

The landing gear is defined in my custom aux mixer file.

It’s currently AUX3, but we should probably make this configurable.

Yes, thank you, I was able to control the landing gear through and only through AUX3 passthrough - I don’t know why this is hardcoded.