In my app we want to subscribe the person to an .ics calendar file that lives on our server. I can't for the life of me figure out how to do this.
Subscribe to calendar
Assuming you have a webcal URL for it, just call UIApplication's open(_:options:completionHandler:) function to open the webcal URL, the system will handle the rest.
The 'webcal' part was actually the piece I was forgetting. Thanks.