There is no backend for sitemap. You can, however, configure which apps can be searched by clicking configuration

The following sitemap XML URL can be submitted to Google Webmaster Tools, Bing, Yandex, Yahoo and other search engines to help them crawl your website better.

Your sitemap can be found here:

This is a demo site, many functionalities have been disabled. The drag and drop functionality also works, but it will not move the object since all write access to the database has been disabled for this demo