add user – ID code of google analytics tracking code google analytics

Hello , I need your help , I have already inserted the google analytics code in the file functions . php son of my subject
add_action(‘wp_head’,’my_analytics’,1,20);

function my_analytics() {
?>
<script>
(function(i,s,o,g,r,a,m){i[‘GoogleAnalyticsObject’]=r;i[r]=i[r]||function(){
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,’script’,’//www.google-analytics.com/analytics.js’,’ga’);

ga(‘create’, ‘UA-54064230-1’, ‘auto’);
ga(‘send’, ‘pageview’);

</script>

<?php
}
Now I need to add the user id that has the following código.? as I have to add? thanks in advance
ga(‘set’, ‘&uid’, {{USER_ID}});