You are shit out of luck with Google Sites, every time you save/update your site, the embed/iframe tree changes. And I’ve not got a suggested fix for that, other than don’t use Google Sites. I need to site down (and sign up for google sites) and try and find a fix when I get some free time
Not until it’s on godaddy and theres a broken page to look at.
Edit: This might work for Google Sites:
<div id="twitch-embed"></div>
<script src="https://embed.twitch.tv/embed/v1.js"></script>
<script type="text/javascript">
new Twitch.Embed("twitch-embed", {
width: 800,
height: 600,
channel: "amyandjesse",
parent: ['sites.google.com', 'www.gstatic.com', window.location.host]
});
</script>