Welcome to the forum! 
In the future, please use words, not screenshots. Uploading images makes forum backups larger. I’ve removed your screenshot as it does not help anyone help you. FYI, one can take a screenshot of a single application with Alt+PrtSc. We don’t need to see your whole desktop.
From the screenshot, I see you’re using Brightness Controller, maybe my brightness-controller-git AUR (Arch User Repository) package? FYI, Brightness Controller uses ddcutil. It does not support laptop displays, only external monitors.
Either way, more details about your system would be helpful. The instructions are included in the second link below: