A question about Addon Domain

[Likquor]

Hi guys, where do i put the files to for an addon domain?

To what i understand, if i put an addon domain example1.name.jp , it creates another folder under public_html/ , becoming public_html/example1.name.jp

But when i upload files to public_html/example1.name.jp/folder/item.php , i cant access the .php file by putting example1.name.jp/folder/item.php into the browser. ( Got a 404 error )

What am i doing wrong? Thanks in advance.
Edit:
As i want my website to show example1.name.jp in the browser as what i got from afraid.org , i do not want to park the domain ( as to what i understand will display the original one like example.elementfx.com ). Thats why i want to use an addon domain but i cant seem to get it to work.

Any help please?

 

[Christopher]

Where you add a addon domain, it should show you where the folder for it is.