Plain HTML

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <title>My site</title>
  </head>
  <body>
    <!-- your page -->

    <script
      src="https://sdk.cashbackhive.com/sdk.js"
      data-key="cbh_pk_your_publishable_key"
      async
    ></script>
    <script>
      window.addEventListener("cbh:ready", ({ detail: { sdk } }) => {
        // use sdk
      });
    </script>
  </body>
</html>