First run pip install -r requirements.txt.
Then run main.py.
If the application doesn't respect the system theme and it bothers you:
pip uninstall PySide2- try this guide to build from source.
If app doesn't stop with Stop button (Ctrl+F2) in PyCharm, you can still close with Ctrl+W or close button from inside the app, or set environment variable PYDEVD_PYQT_MODE to pyside. This should also fix debugging breakpoints not working.