Press the keyboard backlight key, usually Fn + Spacebar
Look for a key with a keyboard light icon on the top row
Press Fn + the key with the backlight symbol if Spacebar does not work
Use Lenovo Vantage to enable or adjust keyboard backlight settings
Check your model’s manual if the keyboard does not have backlighting
Restart the laptop if the backlight is not responding
Update Lenovo keyboard or system drivers if needed