Khan Academy probably has a CORS policy to prevent that. That being said, if you have a proxy, you can get it just fine.

Ah, okay. So, does that mean I can't use it in any way in a Khan Academy program, or are there certain expectations? And, is it possible to make an embed program, and be able to set the width and height, and have the page adjust? I'm trying to implement it so that it's just taking 500 pixels, but I've got no progress so far.

The network tab in chrome devtools can help you figure out for yourself how to make different requests.  It records outgoing and incoming requests so you can view them.

Hi Μɑɠɱɑ,

Our Help Center is powered by Zendesk, so you would need to use their API to fetch data from here. We don't have any control over their endpoints or what information is available from them, so you would need to consult their documentation for more information.

I hope this helps!