The app doesn't detect your piano and you don't know if the problem is the app or your own hardware? So that you can check this, we have developed our own MIDI Connection Test Tool, which you can use at this link: https://latouchemusicale.com/en/web-midi-test-keyboard/

If you use this tool and your piano is not recognized on it either, then the connection problem is most likely due to your hardware (defective MIDI-USB cable, need to install a driver to recognize your piano, cable connections not configured correctly, ...). If the connection works on this tool, then the problem comes from the application and we invite you to send us an email to contact@latouchemusicale.com so that we can solve your problem as soon as possible.