How can i implement screen sharing in flutter using Agora?

Question

i am build screen sharing using agora here is source code (base)

here is code for switch host

Future<void> _switchHostAndUpdateScreen() async {
if (isHost.value) {
  // Switch to audience role
  await engine!.setClientRole(role: ClientRoleType.clientRoleAudience);
  engine!.enableLocalAudio(false);
  engine!.enableLocalVideo(false);
  engine!.disableVideo();
  engine!.stopScreenCapture();
  isHost.value = false;
} else {
  // Switch to host role
  await engine!.setClientRole(role: ClientRoleType.clientRoleBroadcaster);
  if (isJoined.value) {
    await engine!.enableAudio();
    await engine!.startScreenCapture(const ScreenCaptureParameters2(captureAudio: true, captureVideo: true));
    isHost.value = true;

    await engine!.startPreview(sourceType: VideoSourceType.videoSourceScreen);

    // Update channel media options
    await _updateScreenShareChannelMediaOptions();
  }
  _updateScreenShareChannelMediaOptions();
}
setState(() {});

}

got update screen

Future<void> _updateScreenShareChannelMediaOptions() async {
final shareShareUid = int.tryParse(widget.localUidController);
sharingRemoteUid.value = shareShareUid ?? 0;
if (shareShareUid == null) return;

await engine!.updateChannelMediaOptionsEx(
  options: ChannelMediaOptions(
    publishScreenTrack: true,
    publishSecondaryScreenTrack: true,
    publishCameraTrack: false,
    publishMicrophoneTrack: true,
    publishScreenCaptureAudio: true,
    publishScreenCaptureVideo: true,
    autoSubscribeAudio: true,
    publishMediaPlayerAudioTrack: true,
    clientRoleType: isHost.value ? ClientRoleType.clientRoleBroadcaster : ClientRoleType.clientRoleAudience,
  ),
  connection: RtcConnection(channelId: widget.channelId, localUid: shareShareUid),
);

}

now i i want to switch user then current host become audience and audience become host but new host screen is not visible even after allowing and start screen sharing

Thanks in advance