Clicking Remix to Edit then Edit Fullscreen in the embedded editor leads to a 404 page…
Example: https://docs.launchdarkly.com/guides/tutorials/first-flag#remixing-the-lab-app
If you click on the “Remix to Edit” button in the embedded editor, it creates a remixed app in the iframe. But then if you click on the Edit Fullscreen button, you’re taken to the following URL:
https://glitch.com/embed/function(){var%20e;return%20null===(e=i.currentProject())%7C%7Cvoid%200===e?void%200:e.editorUrl(i)}
Which leads to a 404 page.