I get the following error when I ran the live streaming demo

Hi,

Thanks for the product trail, I follow the instruction in https://github.com/de-id/live-streaming-demo, and I got the above error when I press the start button.

The status shown on the browser is:

ICE gathering status: complete
ICE status: connected
Peer connection status: connected
Signaling status: stable
Streaming status: empty

How can I solve the problem? Thanks again.