I have been looking everywhere to make my dell XPS 13.3 running 18.04 LTS adjust the screen brightness automatically. Initially I found that wildguppy which I did manage to install but it is not working. Then I installed the dconf which does have an automatic brightness setting but flipping the switch, once again, does nothing! Then I went to the BIOS and found a dynamic brightness adjustment sth option which was already enabled.... so nothing there too How can this be possible? How can there be absolutely no way to automatically adjust the brightness on 18.04? I hear this feature exists in 20.04 but I cant upgrade, yet...
sudo do-release-upgrade -df DistUpgradeViewGtk3
from a terminal. Then the GUI will pop up telling you the release notes for 20.04, along with the option to upgrade. If you'd rather wait, you will automatically be shown the update when the first point release (20.04.1) becomes available (probably in mid-June to July)