I use the Fn+ buttons with the -sun and +sun on them, and the brightness doesn't seem to change. I have also tried to change the brightness on the bar at the top right. Neither of these seems to work, I googled the problem, but it doesn't seem to be for Ubuntu 20.04 LTS. I could change the screen brightness when I switched to windows 10.
This is the link I was looking at but for the previous versions of Ubuntu.Will the solutions they propose still work or do I have to find another way? I cannot change the screen brightness