I just downloaded Music Maker 2019 Premium. Audio from projects seems to work normally but I do not hear audio when I press on the keyboard on the main screen.
Hopefully your problem is as simple as the following. This is something that happens to me, and I'll just paste something I put in another thread:
This happened to me before. There is one thing I noticed quirky that happens in MMM. If you don't "trigger" the ASIO or whatever else audio driver you are using, the on-screen and even a Midi keyboard may not output any sound. To trigger the driver, I just click on the play button, or press the space bar. There doesn't need to be anything playing, and you don't have to play for long as the driver is triggered immediately. If you are using Windows 10, you will see a message pop up on the bottom right of the screen that confirms this. A bit annoying, but it works and you only need to do it once.
Hopefully your problem is as simple as that.