Your ROOT_URL in app.ini is https://source.parasitstudio.de:63000/ but you are visiting https://source.parasitstudio.de/wirtz/esp-link/src/commit/f75c1acf955531841b22a13c91743c1a9a530b68/examples/arduino
You should set ROOT_URL correctly, otherwise the web may not work correctly.
Karai Csaba