Follett now provides a variety of widgets to access and/or search your Destiny Discover catalog. The widgets are accessed by clicking on the Destiny Discover link under the Catalog tab. Once in Destiny Discover click on your login and select Widgets from the dropdown menu. The "Widget Factory" page will open.
Then follow these steps.
Because you are logged into your library site when you copy the code, the widget "knows" to search your catalog.