How to convert a Parked (Alias) domain to an Addon domain

Question

How do you convert a Parked (Alias) domain to an Addon domain?

Answer

Warning: Email is NOT removed when you remove the Parked domain. However, it is advised that you create a backup of the account before performing any changes.

How to generate a backup of my entire cPanel account from the command-line interface?

Backup for cPanel - full-backup

The first thing you need to do is verify whether Restrict document roots to public_html in WHM at Home / Server Configuration / Tweak Settings is On or Off.

1. Log in to cPanel as the user for the account with the parked domain.
2. Open the Domains interface.
3. Click the Manage button to the right of the domain you want to add as an Addon domain.
4. Click the Remove Domain button.
5. Click the Yes, Remove This Domain button.
6. In the Domains interface, click the Create A New Domain button.
7. Enter the removed parked domain's name to add in the Domain text box.
8. Deselect the Share document root (/home/username/public_html) with “domain.tld” option.

9. In the Specify the directory where you want the files for this domain to exist text box, enter public_html if the Restrict document roots to public_html Tweak Setting is off. 
   
   If the "Restrict document roots to public_html" Tweak Setting is on, remove any text in the text box.

   Note: If you do not want the domain to share the contents of the primary domain, enter a different folder name in the "Specify the directory where you want the files for this domain to exist" text box.

10. Click the Submit button.

Additional Resources

How to place document roots for addon/subdomains outside of public_html