Zoom meetings to custom live streaming to RTMP server

Hi

I have configured custom live stream in Zoom account console.

When I start the meeting and click to send to live stream from More option, it waits for a minute and then stops. Check the attachment.

I am not able to figure out what the problem is.

I have configured the Nginx RTMP server, and tested with ffmpeg sending mp4 file as stream. I could able to run the RTMP URL in VLC player. I mean, from RTMP configuration, I am sure things are correct.

I don't understand what is wrong here. Is there a better way to validate what is going wrong?