I have done everything as far as I know but Finnish letters ä and ö are not working when you trying to control phone screen with the app/PC. Yes, you can write for example a message with the app with ä and ö letters without problems if you are not trying to do that with the phone screen control. I use Microsoft Swift Keys as my keyboard app in Android and my hardware is Logitech MX Keys. I would have wanted to write people's names with the keyboard in the smartphone's Contacts application but now it seems impossible.