I need your help. I set up a WiFi access point on an ubuntu 18.04 server edition with netplan. It is said somewhere in the netplan documentation that hostapd config is used...I do not know if it is right but it does not work to me. How or where can I set instruction to turn the AP in 5GHz mode or to choose the channel? I f any one has a solution, it would be great!! Thank you in advance.