1. Log in to your cPanel account.
2. Find and click the "Addon Domains" option under the "Domains" section.

3. Enter the required details:

• New Domain Name - The domain you want to add to your account.
• Subdomain/FTP Username - Create a username associated with the new domain.
• Document Root - The directory where files for this domain will be stored.
• Password - Set a password for the new user.
• Password (Again) - Confirm the password.

4. Click the "Add Domain" button to complete the setup.

Note: This will only work if the domain’s DNS servers are configured to use the same nameservers as your primary domain.