Here is an example of using the Navigation Rail 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-navigation-rail></uwc-navigation-rail>
<script>
const nav = document.querySelector("uwc-navigation-rail");
nav.menuItems = [
{ icon: "search", label: "search", onClick : ()=>{alert ("search button clicked!");}},
{
icon: "menu", menuItems: [
{ label: "search1", action: () => { alert("menu button clicked!"); return false; } },
{ label: "search2", action: () => { alert("menu button clicked!"); } },
{ label: "search3", action: () => { alert("menu button clicked!"); } },
]
},
{ icon: "restore", label: "restore", onClick : ()=>{alert ("restore button clicked!");} },
];
</script>
</body>
</html>