It's easy to add external source to you interactive page. We have added multiple methods to include your external page:

Code
Type in your custom code or embed code directly in the page

External link
Choose an external https link to include in your page. This will generate an invisible iframe.

Upload html content
For more complex situations you can upload your HTML content through our FTP server. In the page you can select the specific file you would like to include. When using the publication offline or in our iPad app, all sources will be downloaded.