Playing background music from external device when I am on Zoom session on my Windows 10 laptop

[Nabankur]

When I sing on Zoom using default microphone and speaker of my Windows 10 laptop, my karaoke music from my mobile does not reach the participants. Even when I use a Bluetooth microphone and connect my mobile with this microphone my voice is heard clearly but the music is not heard by the participants. What should I do? I am not the host, so I can't share my screen / computer audio. 

[BounceHouse]

I have a similar issue.
I teach online singing and my students can't hear my piano in background or even my sounds when I sing instead of talking.

Did you find a solution?