Icloud caldav for kiosk, but make it read only

Looking to see if anyone has done something like this or could possibly advise. I am trying to get a kiosk display going. looking decent overall but aside from the kids maybe toggling some lights on and off I don’t want to ability on the screen to add an event to the calendar.
I’ve tried to mess around with putting the webcal address in caldav, changing it to https, no go. thought maybe the remote calendar integration would work but couldn’t that going.
Any ideas on this?