Add Google Analytics Code in WordPress Function.php file

Put this Code in your function.php inside wordpress.
This code is adapted by some other Developer.

add_action('wp_head', 'wpb_add_googleanalytics');
function wpb_add_googleanalytics() { ?>

<!-- Global site tag (gtag.js) - Google Analytics -->
<script async src="https://www.googletagmanager.com/gtag/js?id=UA-157150922-1"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());
  gtag('config', 'UA-157150922-1');
</script>

<?php }