What is the Caldav link for the birthday calendar?

The birthdays from the address book didn’t sync anymore with the calendar app. In the process of solving the issue I deleted the birthday calendar. Now I want to add it again; what is the caldav link?

Regain your privacy! Adopt /e/ the unGoogled mobile OS and online servicesphone

should be this one - edit the “yourusername”


Thanks a lot for the info! Unfortunately, when I try to add a Caldav calendar to the Calendar app, I get the message ‘failed to fetch app details’, so I cannot test if it works.
EDIT: I now installed DAVx5 and managed to add the CalDAV account to the Calendar app, but now all my appointments in the calendar are doubled and I still don’t have the birthdays.