Turn your Mac keyboard’s backlighting on or off
If your Mac laptop has a backlit keyboard, you can adjust the level of backlighting when you’re using your Mac in low light conditions or turn off backlighting.
Manually adjust keyboard backlighting or turn it off
Do one of the following, depending on your Mac model:
On the keyboard, press the increase brightness key
or the decrease brightness key 
. To turn backlighting off, keep pressing .In the Touch Bar, expand the Control Strip, then tap the increase brightness button
or the decrease brightness button . To turn backlighting off, touch and hold .
Automatically adjust backlighting in low light conditions
Choose Apple menu
in the sidebar. (You may need to scroll down.)Turn on “Adjust keyboard brightness in low light” on the right.
Automatically turn backlighting off after a period of inactivity
Choose Apple menu
Click the pop-up menu next to “Turn keyboard backlight off after inactivity” on the right, then choose a time.
Tip: The light sensor is located at the top of your computer near the camera; make sure that area isn’t covered when you use your Mac in low light conditions.