1. Log in to your personal account https://billur.com
2. Go to the "Domains" -> "Manage DNS" section
3. Select the domain you need and click the "Edit Zone" button
4. Click on the "Add record" button, select the resource record type A and specify the values in the NAME and RDATA fields.
Create a new subdomain named ‘*’ (asterisk, no quotes) and a web server IP that will host all subdomains.
Example: * A 8.8.8.8
5. To complete the operation, click the "Save Changes" button