app.html

<!DOCTYPE html>
<html lang="en" {{ HTML_ATTRS }} class="hidden">
  <head {{ HEAD_ATTRS }}>
    <script
      async
      src="https://www.googletagmanager.com/gtag/js?id=G-HBV7K2PRX6"
    ></script>
    <script>
      window.dataLayer = window.dataLayer || [];
      function gtag() {
        dataLayer.push(arguments);
      }
      gtag("js", new Date());
      gtag("config", "G-HBV7K2PRX6");
    </script>
    {{ HEAD }}
  </head>

  <body {{ BODY_ATTRS }}>
    {{ APP }}
  </body>
</html>