Here is an example of using the Accordion in a plain html page:
<html>
    <head>
        <link href="https://developer.temenos.com/uux/base.css" rel="stylesheet" />
        <script src="https://developer.temenos.com/uux/unified-ux-web.min.js"></script>
    </head>
    <body>
        <uwc-accordion>
            <uwc-expandable-card heading="Section 1" description="Section 1" expanded>
                Content for the first section.
            </uwc-expandable-card>
            <uwc-expandable-card heading="Section 2" description="Section 2">
                Content for the second section.
            </uwc-expandable-card>
        </uwc-accordion>
    </body>
</html>