Set the data-vars-ga-label to the document.URL for dynamic custom event link label

941392-mi-dynamic-link-label.php

<?php

/**
 * Add to Child Theme's functions.php.
 */
add_action( 'wp_footer', function () { 
  if (is_page ('2')) { 
?>
  <script>
	// Dynamic Label Snippet
	let dl941392 = document.querySelector("#dynamic-label"); // or document.querySelector("a");
  if ( dl941392 ) {
    dl941392.setAttribute("data-vars-ga-label", document.URL);
  }
  </script>
<?php
  }
} );

Live demo on CodePen: https://codepen.io/marklchaves/pen/dyMVZbV?editors=1011