title: Add onClick attribute to WP add_query_arg()
body: <p>I have Google Conversion Tag that needs to add to the WP <code>add_query_arg()</code> function.. I tried to Google it but there is no similar info that I am looking.</p>
  
  <p>My concern only is to add another attribute of <code>onclick="return gtag_report_conversion();"</code> to the result of this code:</p>
  
  <pre><code>$urls = add_query_arg ( 'ver', $value[ 'user_ver' ], get_permalink ( $landing_page ) );
  </code></pre>
  
  <p>Update</p>
  
  <p>We've decide to put the onClick attribute to where the download button is present on an actual interim page, instead of having modifying the <code>add_query_arg()</code>.</p>