Ubuntu Server 18.04 Unmanaged Wifi

Keywords´╝Ü linux wifi ubuntu-18.04 ubuntu-server

Question: 

I'm working on Ubuntu Server 18.04 and I'm trying to setup the Wifi.

When I do nmcli d to have the list of available network interfaces, I have the following output:

DEVICE    TYPE    STATE        CONNECTION
wlan0     wifi    unmanaged    --

On the other hand, the command nmcli general shows me:

STATE        CONNECTIVITY    WIFI-HW    WIFI
connected    full            enabled    enable

What does it mean and how to solve it ?

I don't have any other wired connection so the wifi it's my only solution to have internet on my device. Thus, I cannot install any new package to solve my problem.

Thanks

Answers: