Your ROOT_URL in app.ini is https://source.parasitstudio.de:63000/ but you are visiting https://source.parasitstudio.de/wirtz/OpenAudio_ArduinoLibrary/src/commit/17010218ce8a6f1862652eaa70b966f02084e9c0/examples/AudioTestPeakRMS
You should set ROOT_URL correctly, otherwise the web may not work correctly.