How to link calendar to an Email Address

I would like to link an email address to the nexcloud calendar and configure it with mail apple calendar app and other calendars. I guess this should work with CalDav, right?

But I don’t understand how I link a calendar to an email? Is it possible to link for example to a calendar in nextcloud, so that if I get an calendar invitation from someone extern I can click on “attend” and the external user will get a notification that I accepted the calendar invitation?

Thanks for your help