Flutter web_socket_channel cannot send ByteBuffer

Question

My Flutter app uses a web socket to send the mp3 file to the server directly. I need to slice mp3 file to small ByteBuffer. I use web_socket_channel but when I send ByteBuffer, the _channel onDone immediately and the server has not received data from the app.

  void sendData(ByteBuffer data) {
    _channel.sink.add(data);
  }


   listenToMessage() {
    if (_channel != null) {
      _channel.stream.listen(
        (message) {
          print("websocket listen: $message");
        },
        onDone: () {
          print("Websocket listen onDone");
        },
      );
    }
  }

I saw method sendByteBuffer in Websocket in dart:html lib, but cannot use in the mobile app.