Adding VistorID to a URL parameter

Hi,

I would like to add the Visitor ID of the site visitor on the page as a outbound URL parameter on same page. My code looks like this:

<html>
<head>
<script type="text/javascript">
<!--
function delayer(){
    window.location = "http://thedomainIamlinking.com?something="something"&source="MatomoVisitorID"
}
//-->
</script>

    <!-- Matomo -->
<script type="text/javascript">
  var _paq = _paq || [];
  /* tracker methods like "setCustomDimension" should be called before "trackPageView" */
  _paq.push(['trackPageView']);
  _paq.push(['enableLinkTracking']);
  (function() {
    var u="//myreporturl.com";
    _paq.push(['setTrackerUrl', u+'piwik.php']);
    _paq.push(['setSiteId', '7']);
    var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0];
    g.type='text/javascript'; g.async=true; g.defer=true; g.src=u+'piwik.js'; s.parentNode.insertBefore(g,s);
  })();
  var visitor_id;
_paq.push([ function() { visitor_id = this.getVisitorId(); }]);
</script>
<!-- End Matomo Code -->
    
</head>
<body onLoad="setTimeout('delayer()', 1000)">

</body>


</html>

What do I need to add instead of “MatomoVisitorID” in the URL above to make this work?

Thanks in advance for your help!