Just add the code below to the head. If you want to hide the banner for some reasons, add ?noban to the URL.
<script>
(function (i, s, o, g, a, m) {
a = document.createElement('script');
m = document.getElementsByTagName('script')[0];
a.async = 1;
a.src = 'https://demo-banner.circul8.com.au/index.js?t=' + 1 * new Date();
m.parentNode.insertBefore(a, m)
})(window, document, 'script', 'https://demo-banner.circul8.com.au/index.js');
</script>