This article will give you a step by step guide on how to add Addon Domains to your website from your cPanel.
Sign into your cPanel and follow these steps:
1) Go to Domains and click Addon Domains
2) Enter the new desired domain name (this will automatically fill in the Username and Document Root boxes, but you may change them if you like)
3) Enter the desired password
4) Click Add Domain
5) You will then get a confirmation page saying that your additional domain has been created
This concludes how to add Addon Domains to your website from your cPanel