iBooks Author: Add HTML
You can add an HTML5 widget (with the extension .wdgt), which you can create with a text editor or by using a web content creation app.
Add an HTML5 widget
Choose HTML from the Widgets pop-up menu in the toolbar.
In the Widget inspector, click Interaction, click Choose, and choose an HTML5 widget.
HTML5 widgets must include a Default.png file to display when the widget isn’t open.
If your HTML5 widget includes video and audio, the suggested file formats are MP4 (for video) and M4A (for audio).Important: iBooks Author doesn’t support HTML5 widgets containing M4V video files or M4P audio files.
To edit the widget, select the thumbnail image, click Edit HTML, make your changes, and click Done.
HTML5 widgets are set to “Show object as a thumbnail” and appear as a thumbnail image in iBooks. In the completed book, readers tap or click the thumbnail to interact with it.
To change the widget’s thumbnail image, drag a new image to the thumbnail.
You can also drag an HTML5 widget directly to the book page.