HTML Version
Simply add this script tag at the end of your </body> (or anywhere else on the page).
<script async src="https://scripts.pageviews.online/latest.min.js"></script>
JavaScript Version
You can also install the script programmatically using JavaScript with this code:
const script = document.createElement("script");
script.src = "https://scripts.pageviews.online/latest.min.js";
script.async = true;
document.head.appendChild(script);