You connect to your calendar and contact list with CalDAV and CardDAV connection credentials:
- First you create a user account as explained under Creation of mail user accounts
- With your user account, log on to Webmail: https://webmail.skymotor.dk
- From the Webmail overview page, select the menu item "Configure calendar and Contacts client", where you will find your connection credentials to your calendar and contact list
Detailed information on how to set up the calendar and contact list can be found here: https://docs.cpanel.net/knowledge-base/webmail/how-to-set-up-calendars-and-contacts/