That would be an environment variable. It has to be written into a file sourced
by your DM, each has their own standard. For KDE/sddm, you can look into
/etc/sddm/Xsession to see which file correspond to your system (it's different
whether you use bash or zsh or whatever else).

Cheers,
                 Ludovic

On Thu, 28 Jul 2022, o1bigtenor via Dng wrote:

>Hmmmm - - - -setting it system wide - - - - would that not be running as
>root the command export SDL_VIDEOALLOW_SCREENSAVER=1 ?
>
>Is that only invoked with a system restart?
>
>TIA