Admin Module does not work, iframe set to "display:none"

In case I try to host a module admin view, I receive the following view

This is due to the fact, that my iframe gets set to „display:none“

manifest.xml excerpt

  <module name="Keepoala"
            <label lang="de-DE">Keepoala</label>

Why is that the case? My website renders perfectly

To do this you need to confirm that your code has been loaded via a javascript snippet.

Here is an example of the javascript snippet.

AppTemplate/base.html.twig at master · shopwareLabs/AppTemplate · GitHub → window.parent.postMessage(‚sw-app-loaded‘, ‚*‘); must be called.

Also once again our documentation.

@SvenDenter , it works fine now. But would there be a way to set this timer > 5 seconds. Using a dev-environment my app builds in approx 6 seconds. Of course the app loads only 0.5 seconds after an optimized build, but during development I would like to check some things live. Maybe if shopware runs in debug mode (via dockware) this could be set higher?