password protect desktop mode from sleep (onscreen keyboard in SDDM)

i installed bazzite on my deck.
i'm trying to somewhat secure it so i'm not as concerned about being logged into my email and youtube on the desktop mode. i want to pasword protect it when i put it to sleep in desktop mode (ideally only when i'm not on my home network)
i found this setting which seems to do what i want but i can't get the onscreen keyboard to show up