We are trying to add support for OneBox on some of our domains ( https://makecode.com/_4u98ff3eVU1F or falling duck - Microsoft MakeCode ) to our hosted discourse forum. Both pages are oEmbed/open graph ready (tested in iFramely http://iframely.com/debug?uri=https%3A%2F%2Farcade.makecode.com%2F13217-23381-09800-62258 ).
When I copy the link in the editor, I see the spinner and the call to the /onebox?.. web api which returns 404.
- we tried to configure the onebox whitelisting but it did not fix the issue.
- Is there a way to validate a page?