I prefer to use command line because mostly server does not installed window manager. I need to familiar to use command line in any situation.
To show wifi radio enable
# nmcli radio wifi
enabled
To turn on radio wifi
# nmcli radio wifi on
To list available wifi
# nmcli device wifi list
IN-USE BSSID SSID
...
To rescan available wifi
# nmcli dev wifi rescan
To connect to wifi access point
# nmcli device wifi connect "[your_SSID]" password "[your_password]"
...
To show connection
# nmcli connection show
NAME UUID TYPE DEVICE
...
Note: parameter dev is short from device
