How to set the sharing service from public to private

I follow the tutorial Hololens 240 https://docs.microsoft.com/en-us/windows/mixed-reality/holograms-240. but in chapter 3 shared Coordinates,the PC which launch the sharing service should set the sharing service to the private network if the firewall prompt appears. but the problem is i set it to public network wrongly. Is there any way to set back to the private network? it seems that i should set it in Windows Defender Firewall panel,but i don`t know which app should be changed from public to private. any bits of help are appreciated. Many Many thanks.I struggle on this for 3 days.