<script> is not executed or how to implement a page counter

General
1

Hello,

i want to add a page counter. The HTML code is

<a id="someid" href="https://www.internetanbieter-experte.de">www.internetanbieter-experte.de</a>
<script language="JavaScript" src="https://www.besucherzaehler-kostenlos.de/js/counter.js.php?count=1&id=abcdef&start=0&design=1e"></script>

I tried both UI.getCurrent().getPage().executeJS() and a new PolymerElement in a seperate .js file. The PolymerElement works fine except for that any code in a <script> block is not executed.

Any hints appreciated!