Here is an example of using the Period Combobox 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-period-combobox id="periodCombo" label="Select"></uwc-period-combobox>
<script>
const comboEl = document.getElementById("periodCombo");
comboEl.maxPeriods = "360D,100W,360M,50Y";
</script>
</body>
</html>