While installing Retrowave 3.8.50 on my new Asus i7 laptop, I encountered a problem with my keyboard. On modern PCs, these are backlit. Here are the command lines that allowed me to overcome the problem. Have a good day
OFF: echo 0 | sudo tee /sys/class/leds/asus::kbd_backlight/brightness
LITTLE: echo 1 | sudo tee /sys/class/leds/asus::kbd_backlight/brightness
MAX: echo 2 | sudo tee /sys/class/leds/asus::kbd_backlight/brightness
I'm surprised. On my laptops the 'Fn+Space' key combo generally just works out of the box. 
Not for me, but now it's all good
Can you verifiy if the tool to change the keyboard brighness works?
~ ❯❯❯ elive-keyboard-backlight
Usage: elive-keyboard-backlight up|down|toggle|toggle_full|get|set|info|max [value|steps]
examples:
elive-keyboard-backlight get
elive-keyboard-backlight set 50%
elive-keyboard-backlight toggle 4 (toggle the light in steps of 4)
elive-keyboard-backlight toggle_full
~ ❯❯❯
sudo elive-keyboard-backlight
When I use the command:
my keyboard turns off.
But when I type it again, the keyboard turns on again. The 50% dimming also works fine.
elive-keyboard-backlight set 50%
~>>>elive-keyboard-backlight set 50%
Updated device 'asus::kbd_backlight':
Device 'asus::kbd_backlight' of class 'leds':
Current brightness: 2 (67%)
Max brightness: 3
~>>> elive-keyboard-backlight toggle_full
elive-keyboard-backlight toggle_full
I didn't know Elive had this feature. Thanks.
Elive has so many features people don't know, I must publish them in the website 