How do I silence the voice line when creating an MP3 file

I have created a song for voice and piano. I want to export it as an MP3 audio file, but I only want the file to play the piano accompaniment part, not the voice part. What I got was the piano and a choral simulation. How do I delete the choral part when I export the file? I am using MuseScore 3.

Thanks,
Rhonda