1. Log into your cPanel account.
2. In the "Domains" section, click on the "Domains" icon.
3. Under "Create a New Domain" you should enter your addon domain name.
New Domain Name: your addon domain name like example2.com
Subdomain: it will be automatically filled in by cPanel.
Document Root: it will be automatically filled in by cPanel.
4. Click on the "Submit" button.
If the domain is successfully added, you will see a message like this