ICS is the universal format used by many email and calendar applications as Microsoft Outlook, Google Calendar and iCal from Apple.
In order to download it from your Octorate platform, go to ROOMS > EDIT (you have to do it for each rooms you have).
Picture 1 - Click to enlarge
In the page of the options of the room, if you go down left you can find USEFUL LINKS. You can click on the orange button to copy the calendar, or you can click on the blue one to download it.
Picture 2 - Click to enlarge