Once you have successfully setting up your add-on domain, you can create an FTP user through your account’s cPanel to access to your add-on domain directory directly.
For example, by default you have one primary domain. You already added another domain in the same host. Let’s say, your primary domain is called (primarydomain.com) and your add-on domain is called (addondomain.com).
So, what should your FTP settings be for your add-on domain if you wish to connect to your add-on domain directly?
You can refer to the following settings to connect:
Password: password you created for the user
Directory: / or blank
Besides, you can always use the main FTP account and going to the add-on domain’s subfolder under public_html to access your add-on domain folder directory instead.