Render video in sequncer. Why the video does not have sound?

I try rendering movie and put some sound cue. but the video is silent, no sound…
why?? and how can I put that sound to video

As of the end of last year the ability to render out video from Unreal with Sound is still not a feature.

Here is one of the many threads about it that has a response from one of the Epic team from the end of November last year.

do you have any solution?

Not for directly getting it out of Unreal.

But what you could do instead of capture the video using sequence to ensure it’s quality, than use something for screen capture and in a video editing package just use the audio from the screen captured version.

Honestly until Epic adds the audio capture to the video output it’s just a matter of finding a way to record audio and than merging them together in an outside package.