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/b056dab06e0f90a9ad3e50ae8e2b1c2367565599/examples/SpectralDenoise
You should set ROOT_URL correctly, otherwise the web may not work correctly.