that works as expected. Ok. Next two steps. Edit you container. Switch to Manage Variables. Create new variable. Choose Matomo Configuration. Go down to Tracking Request Target Path and switch from piwik.php to js/
The idea behind containers: Insert the matomo Tag Manager code into your website only once. If you work with a matamo expert, they can configure matomo without having to change the code on the live website. The container changes every time you change the configuration.
You can change the endpoint in the variables. The moment we switch from piwik.php to js/ your website sends data to matomo.example.com/js/ instead of matomo.example.com/piwik.php
If you use the file manager from App settings and open js/index.php you see
If you open tracker.php you find the require once which throws errors in the logfile.