I cannot setup wifi.

[Getafix17]

I tried to setup wifi using different methods, but none seem to work.
iwconfig
lo no wireless extensions.

eth0 no wireless extensions.

wlan0 IEEE 802.11 ESSID:off/any
Mode:Managed Access Point: Not-Associated Tx-Power=31 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Power Management:on

[Getafix17]

ip addr show wlan0
3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether dc:a6:32:ae:9b:bd brd ff:ff:ff:ff:ff:ff
alexf@ubuntubittle:$ sudo systemctl restart systemd-networkd
[sudo] password for alexf:
alexf@ubuntubittle:$ sudo netplan apply
alexf@ubuntubittle:$ sudo nmcli device wifi connect 'Tenda_Extender' password '12345678'
Error: No network with SSID 'Tenda_Extender' found.
alexf@ubuntubittle:$ nmcli device status
DEVICE TYPE STATE CONNECTION
wlan0 wifi unavailable --
docker0 bridge unmanaged --
eth0 ethernet unmanaged --
lo loopback unmanaged --
alexf@ubuntubittle:~$ ip addr show wlan0
3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether dc:a6:32:ae:9b:bd brd ff:ff:ff:ff:ff:ff