As an example, this site works in the same way using Embed
https://www.wheelercentre.com/events/meeting-1-robots
If you look at the underlying source, you'll see
<div class="flarum-discussion__inner" style="max-height: 800px"><iframe class="flarum-discussion__embed" data-view-iframe-resizer='{"maxHeight":800,"scrolling":true}' frameborder="none" src="https://discussions.wheelercentre.com/embed/103"></iframe></div>
It's basically the same - you can also call that URL above directly, and it works.