Should I add Google tracking code in the section of my site ?

Hello,

Google Analytic recommand to add a tracking code in the header something like this :

<!-- Global site tag (gtag.js) - Google Analytics -->
<script async src="https://www.googletagmanager.com/gtag/js?id=UA-1234567890-1"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());

  gtag('config', 'UA-1234567890-1');
</script>

After installing this plugin I searched in the HTML code of my page and I cannot find anything related to Google Analytic, so how does it work ?

Thanks for this great plugin,

Fl