Step 1: Login
Login to your cPanel account and click on the Addon Domains icon under the Domains tab.
Step 2: Add Domain
In the New Domain Name field, enter the name of the domain you would like to add to your cPanel account.
Step 3: Name Directory
Enter the name of the directory which will contain the files for your Addon Domain's public website.
Note: By default this directory will have the same name as the domain you have selected and can be left like this
Step 4: Create Password
In the Password field enter a password for your new Addon Domain. To finish click Add Domain, your domain will now be added to your cPanel account.
Note: This password can be used to access the domain via FTP.