Install iframe Apps
Choose page to set up.
Edit html or Add embed link
-Edit Html method
Your Tab URL must be relative to your Canvas Page and therefore your Canvas URL. Using our previous Canvas Page and Canvas URL settings would results in Facebook loading content from « http://www.example.com/canvas/tab. »
As with a Canvas Page, the amount of space available to your app is bounded by the outer context of Facebook. Since your app is also loaded inside of Facebook Page, the space is smaller (520 pixels) than what is available to on a Canvas Page.