There is no GUI and the command is nmcli and that is part of networkmanager package. The commands are ...

To list the available wifi interface(s):

nmcli d 

To turn wifi on:

nmcli r wifi on

To list available wifi networks:

nmcli d wifi list

To connect:

nmcli d wifi connect {ssid} password {password}

In case it is a hidden network:

One time:

nmcli c add type wifi con-name {connectionname} ifname wlan0 ssid {ssid}

nmcli c modify {connectionname} wifi-sec.key-mgmt wpa-psk wifi-sec.psk {password}

And then to connect:

nmcli c up {connectionname}