I don't know if this fits your use case (you didn't describe what you want to achieve in detail), but commands that can possible help if the screen did lock (or turn off):
loginctl unlock-screenkscreen-doctor --dpms onWasn't that. I want to keep the screen on. No sleep, no lockscreen, no blackscreen, etc.
There is kde-inhibit --screenSaver <command> provided by KDE.
But these days, I would just recommend everyone to use systemd-inhibit --what=idle --why=<because> --who=<myself> <command> instead. Works across desktops and does the same thing.
What should I put in the <command> part?
Not KDE but might be similar: For the MATE desktop it is mate-screensaver-command --inhibit. I would expect something similar for KDE.
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