No sound in WAV output

i am using cubase 10.5. i have connected my casiotone CTS300 to my pc and tried to work with cubase. i have played some notes through piano, and recorded it in cubase midi track. i exported the audio mixdown in WAV format. but when playing file in media player and VLC player, there is no sound. exported file was 4.3mb of weight, but still no sound. same time the notes are good in cubase midi track, i mean sound was good within the cubase software. but no sound in exported file.

kindly help me to solve the issue.

Might be useful to have a screen grab of your Audio Export settings.
Hard to see what’s wrong with no clues.