Studio One with a digital piano coected to computer

I'm very new to music and dont even know if what I want to do is possible.

My AudioBox USB 96 works very well with my microphone (SM58) on Studio One (with Universav Control, btw I'm on Windows 10), such easy to use.

Next, I have a digital piano (casio PX830) with an USB output that I directly coected to my computer (that's the part where I am not sure of what I'm doing). I added the instrument to Studio One exteal devices. The piano driver seems to work well as I can register MIDI notes and I see them on a track. I associated the track with default Impact and my problem is I cant hear anything from this track (tried phones from audiobox and separated speakers).

Sorry for my poor english btw.

If someone can help me I'd be glad.

Thanks