SHA-256.js

<script src="https://cdnjs.cloudflare.com/ajax/libs/crypto-js/3.1.9-1/crypto-js.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/crypto-js/3.1.9-1/hmac-sha256.min.js"></script>
<script type="text/javascript">
function genHash() {
    const ID = '0000';
    const KEY = '000000000000000000000000000000';
    var userId = document.getElementById('USERID');
    var time = new Date().getTime();

    var signature = CryptoJS.HmacSHA256(userId.innerText + ID + time, KEY);
};

genHash();
</script>