Flutter: Using twilio as turn server with webRTC

Question

# 'java.util.List org.webrtc.PeerConnection.getTransceivers()' on a null object reference"

I am creating a screen mirroring application using twilio as a turn server with web rtc. When I call mirrorScreen() The error: Attempt to invoke virtual method 'java.util.List org.webrtc.PeerConnection.getTransceivers()' on a null object reference arises. In order to trace the execution I added several print statements but none of these are executing.

Here is my code:

mirrorScreen() async {
FlutterBackground.enableBackgroundExecution();

  RTCPeerConnection connect =
      await _createPeerConnection().then((conn) {
    print(
        'connected---------------------------------------------------------------------- successfully');
    inspect(conn);
    return conn;
  });

  print('connnnnnnnnnnnected');
}

_createPeerConnection() async {
  try {
    Map<String, dynamic> config = {
      "iceServers": [
        {
          'url': 'turn:global.turn.twilio.com:3478?transport=tcp',
          'username': 'Test SID',
          'credentials': 'Test Auth Token'
        },
      ],
    };

    final Map<String, dynamic> offerSdpConstraints = {
      "mandatory": {
        "OfferToReceiveAudio": true,
        "OfferToReceiveVideo": true,
      },
      "optional": [],
    };

    RTCPeerConnection pc =
        await createPeerConnection(config, offerSdpConstraints);

    return pc;
  } catch (e) {
    print('errro');
  }
}

P.s Neither of the print statement is executing