Google Tag Manager - Image tracking script - Invalid HTML

Im trying to insert the image tracking script as HTML tag, but I always get the error when I want to publish it that the HTML is invalid.

This is what my script looks like:

<noscript><!-- Matomo Image Tracker-->
<img referrerpolicy="no-referrer-when-downgrade" src=";rec=1" style="border:0" alt="" />
<!-- End Matomo --></noscript>