Step 1:

A CAA record tells a certification authority (CA) if it is allowed to issue a certificate for a host or not. The CAA record is optional, which means that if NO CAA record is set, any certification authority is allowed to issue a certificate. If a CAA record is set, it must be taken into account. You can also set multiple CAA records.

Step 2:

Log in to your KAS (Technical Administration) panel and click the menu item Tools -> DNS Settings on the left.

Click the Edit icon right next to the domain and then click on Add a new DNS record.

Step 3:

Select CAA as Type and in the Data field, please enter the desired parameters.

Here are example entries for two certification authorities:

Let's Encrypt: 0 issue "letsencrypt.org"

Sectigo: 0 issue "sectigo.com"

Afterwards please click on Save in order to apply the entries.

Step 4:

The new entry will now show up in the table.

IMPORTANT: After the change it could take up to 3 or 4 hours until the new settings are active.

Step 5:

If you want the CAA record to be also valid for a subdomain (e.g. www), then you must add a CNAME record as well which points the subdomain to the domain.