Parked is something like a shortcut (e.g. in MS Windows a shortcut is a link that points to a computer program or other locations on the computer).
Parked does not create a new directory in which your domain will be located
So you need to add it as Addon Domain ! (of course, first remove it from the system)
If you want to move a website from one domain to another and don’t want to use the parked domain option, then you have to move your website files to a different directory.