Here is an example of using the Checkbox Group in a plain html page:
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<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-checkbox-group name="mygroup" label="My Checkbox Group" helperText="Additional information to help use this checkbox group"></uwc-checkbox-group>
<script>
const group = document.querySelector("uwc-checkbox-group");
group.options = [{ label: "One" }, { label: "Two" }, { label: "Three" }];
</script>
</body>
</html>