calamares-settings-ubuntu/kubuntu/oem/calamares-finish-oem

#!/bin/bash

msg="$(cat <<EOL
You are about to disable OEM configuration mode. The system will boot into the
account setup wizard the next time it is started.

Are you sure you want to continue?
EOL
)";

if kdialog --warningyesno "${msg}"; then
  sddm_file="$(cat <<EOL
[Autologin]
Session=kubuntu-oem-environment
User=oem
EOL
)"
  echo "$sddm_file" | sudo tee /etc/sddm.conf
  kdialog --msgbox 'Done. The account setup wizard will run on next bootup.'
fi