The first step would be to make absolutely sure that you're using the latest version of the add-on, because I don't think you are.
Look at the page's source (the actual source for the page, not the live DOM) the markup for the Twitch embed should look like this:
HTML:
<span data-s9e-mediaembed="twitch" style="display:inline-block;width:100%;max-width:640px"><span style="display:block;overflow:hidden;position:relative;padding-bottom:56.25%"><iframe allowfullscreen="" loading="lazy" onload="contentWindow.postMessage('','https://s9e.github.io')" scrolling="no" src="https://s9e.github.io/iframe/2/twitch.min.html#channel=;clip_id=AcceptableCooperativeYogurtTwitchRPG;t=;video_id=" style="border:0;height:100%;left:0;position:absolute;width:100%"></iframe></span></span>
Or just post the URL for the page shown in your picture. To be clear, I'm talking about the page that embeds Twitch.