{source}
<!-- You can place html anywhere within the source tags -->
<iframe width="560" height="315" src="https://www.youtube.com/embed/x5HSlzRzF0A" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
<script language="javascript" type="text/javascript">
// You can place JavaScript like this<iframe width="560" height="315" src="https://www.youtube.com/embed/x5HSlzRzF0A" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
</script>
<?php// You can place PHP like this
?>
{/source}