Rename matomo.php when using the tracking proxy

Hello!

I am using the tracking proxy (https://github.com/matomo-org/tracker-proxy) to hide my matomo server url.

Now I also want to hide the matomo.php call and I want to move the tracker proxy files to a subfolder.
I tried to edit the files and filenames but that breaks my tracking.

What do I have to do to use another filename for the matomo.php and how can I make the files work in a subdirectory?

Thanks
Splitter