Good day.
You can mute remote (playing) audio on client side using WebSDK function
Stream.muteRemoteAudio()
as we recommended in
this topic. Then you can unmute remote audio with function
Stream.unmuteRemoteAudio()
.
Remote (playing) video cannot be muted on client side.
Publishing audio and video can be muted on publisher side using
Stream.muteAudio()
and
Stream.muteVideo()
correspondingly.
If you wish to mute/unmute stream on server using REST API, it is not possible.