Here is an example of using the File Upload 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-file-upload></uwc-file-upload>
</body>
</html>