Wordpress: insert Google Analytics code.

wp-analytics.php

function my_google_analytics() {     
      <!-- Global site tag (gtag.js) - Google Analytics -->
      <script async src="https://www.googletagmanager.com/gtag/js?id=UA-69841290-2"></script>
      <script>
        window.dataLayer = window.dataLayer || [];
        function gtag(){dataLayer.push(arguments);}
        gtag('js', new Date());

        gtag('config', 'UA-69841290-2');
      </script>
}
add_action( 'wp_footer', 'my_google_analytics' );