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/b1235121463cdaa5cba23569513909a1fadadec5/docs/bootstrap/img
You should set ROOT_URL correctly, otherwise the web may not work correctly.