I think we’ll need more information on what you’re trying to do to make recommendations.
A RW “Offsite” page is just a way to include a link to another website in your navigation. It is not a way to incorporate content from another site into your site.
Do you control both sites? Why do you want the content on the other site and embedded instead of just including that content in your existing site?
You could use an iframe to include the content. That’s essentially what Joe’s Offsite stack does. I noticed that the demo of it on his site does not work either. Perhaps there is a bug that is causing it not to work on your site and his? @joeworkman