If you use Outlook, you can add the shared calendar by following these steps:
If you want to have our calendar overlay your default calendar in Outlook once you have followed the steps above:
If you use the native Calendar application on your iPhone and you want our events to be automatically added to your calendar, follow these steps on your iPhone:
Now, when you open the iPhone Calendar application, our events will be automatically merged in.
These steps are for IOS 14 and later and could be slightly different for other versions.