Can I add addon domains without changing DNS

Unfortunately, you can not add addons this way.

You would need to change name servers for your domains first and only after that you will be able to create the addon domain in your cPanel.

If you would like to keep current name servers of your domain please submit a ticket to our Hosting Technical department and our technicians will assist you with the domain.

However, we strongly advise you to change the name servers to ours in order to avoid any issue