iOS Carddav account verification failed


I am trying to use NextCloud contacts on my iPhone and I keep hitting the “Carddav account verification failed” message. I am using the shared link:"

That you copy the link from and my username and password, I’ve tried some other variations as well. I’m not sure what to do. I’ve searched the site and it seems I found some older postest that didn’t help. Any ideas appreciated!

Using the search function of this forum I found the following information:

Additionally the Nextcloud user guide provides detailed information how to sync data: