You can probably do something like this;

<script>
  let checkForCurrentErrors = setInterval(() => {
   if(__currentPerchanceErrorCount > 0) {
     clearInterval(checkForCurrentErrors)
     errorPage.style.display = 'block';
   }
  }, 10)
</script>
<div id="errorPage" style="position: absolute; z-index: 999; display: none; width: 100dvw; height: 100dvh; background: blue;">
  Testing Error Page <br>
  Please Reload the Page
</div>

It is an interval that checks if there was a perchance error happened. You could also probably have a timeout in which if the page doesn't load for more than 30 seconds, then it would show the error page.

However, these solutions only happen when the page has already been working, meaning, if they just opened up the page, it would still take the Perchance server to send the data first before it loads (where the loading issues might happen), in which case, it needs a server-side code to fire to report that the generator isn't loading.

Depending on the error you want to handle, there might be solutions that we can code and not need the server to provide it for us.

One approach that might work here is to load your feedback button as the very first thing on the page - i.e. before any of the code that could have errors. That way there's always a feedback button hovering in the corner of the page. Or you could have a "loading screen" that sits in front of all your content, and has a feedback button in the middle, and that loading screen is deleted/hidden once you've detected that the page has successfully loaded.

Needs to say a looks like you rolled a snake eye's check your code and try again the perchance logo is a dice cube