How to setup fixed ZHA with channel 6 free on wifi

Hi.

Does anyone know which channel should I set to be fixed for my ZHA in order to avoid interference on the Zigbee device? My WIFI is currently set on 1 and 11 which is make channel 6 free.

I believe I need to reset my Zigbee network to make changes and fixed the channel problem. If yes, how do I reset my ZigBee network? And which ZHA channel should I set as a fixed channel?

Thanks in advances