How to enable keyboard backlight for Ubuntu 18.04 OS on Lenovo Thinkpad L480 laptop

Question

I have tried this option

sudo gedit /etc/dbus-1/system.d/org.freedesktop.UPower.conf

and change setting

<allow  send_destination="org.freedesktop.UPower.KbdBacklight"
           send_interface="org.freedesktop.DBus.Properties"/>

i have changed tag <allow> to <deny> but it didn't work.

Second option i have tried below command on terminal

 xset led 3

This command not work for me. Please help me out from this unnecessary bug.

Answer 1

At least with Thinkpad T480 model the keyboard led seems to be found under tpacpi::kbd_backlight:

So like proposed in comment section,

echo 2|sudo tee /sys/class/leds/tpacpi::kbd_backlight/brightness