@Mazzokun this command line is just for restart domoricz There is no link directly with magic mirror
The command line in terminal (Home/pi/)
Sudo service domoticz.sh status
Just to know if domoticz is on or off
Sudo service domoticz.sh restart
Just to stop and start again domoticz
Follow this link to start domoticz when raspberry boot
https://www.domoticz.com/wiki/Linux
And chapter
Starting Domoticz automatically when the system boots