Matomo tracking blocked

I have 5 web sites on my server and a Matomo install on the main site.
That site is ok and doesn’t get blocked as the tracking url is direct.
All the other sites are not getting correctly tracked because of third party connections being blocked by browsers.
Is there anyway around installing on each domain?
Can’t find anything to assist.

May be my words were confusing.
ALL these examples are on the one shared server account using the Javascript tracker - where Matomo is installed This site collects true visitation data - fail - fail - fail - fail


What’s the alternative to using the URL in this code ?
I tried replacing this var u="//"; with the direct link on the server … home2/public_html/ … no change

<script type="text/javascript">
  var _paq = window._paq || [];
  /* tracker methods like "setCustomDimension" should be called before "trackPageView" */
  (function() {
    var u="//";
    _paq.push(['setTrackerUrl', u+'matomo.php']);
    _paq.push(['setSiteId', '2']);
    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+'matomo.js'; s.parentNode.insertBefore(g,s);