Brightness control is not working

What have you tried:
tried reinstalling graphics driver

What is the error:
When i try to change brightness its not changing and when i went to display setting its shows kscreen not found
What device is this on:
Acer nitro 5

Keyboard buttons don’t usually work out of the box because they can be in many different configurations depending on each manufacturer.

You can add controls and map them to the correct buttons;

https://www.baeldung.com/linux/monitor-brightness-change