Screen goes darker when not interacting

I have an issue with new KDE Majnaro Linux Dbtr.
When I am watching youtube screen goes darker due to inactivity. How can I prolong the timeout perioud in Manjaro for the display? I have checked in display settings and there is nothing there, atleast I did not saw anything.
Also I tried deleting sudo rm /etc/X11/xorg.conf and it is the same.

Check Energy Saving settings instead.