This article will go over creating an Addon Domain under your cPanel account.
Step 1 : Log into cPanel on the account to add the domain on.
Step 2 : Click "Domains" under the "Domains" section.
Step 3 : Click the "Create A New Domain" button.
Step 4 : Enter the domain name to add in the "Domain" text box.
Step 5 : Deselect the "Share document root (/home/username/public_html) with “domain.tld”." option.E
Step 6 : Enter the directory where you want the files for this domain to exist.
Step 7 : Click the "Submit" button.