Configure iOS Contacts

Step 1:

Open your Contacts app, go to Settings then go to Accounts.

Step 2:

Go to Add Account.

Step 3:

Tap on Other.

Step 4: Tap on Add CardDAV Account. 

Step 5: Now insert your CalDAV server address in the Server bar, it'll function the same way for getting your Contacts.

Put in your hugomail address as well to continue.

Step 6:

Once you're connection verifies, you'll be sent back to the accounts page, your CalDAV Contacts account should now be set up and your Contacts should sync after a few seconds. (The image below contains fake example contacts, your own contacts may very)