How to Track Game Notification from GooglePlayGames to Unity UI ??

I am Working on a Project to implement Google Turn Base Multiplayer in my Game and its working well . i am receiving the notification in my GooglePlay Game Service . But i want to receive it in my Unity GUI ...... is there any library i have to Export (I have Already Exported GooglePlay Game Plugin ) Please Help My Code is Given Below

using UnityEngine; using UnityEngine.UI; using System.Collections; using System.Collections.Generic; using GooglePlayGames; using GooglePlayGames.BasicApi.Multiplayer; using GooglePlayGames.BasicApi; using UnityEngine.SceneManagement;

using UnityEngine.SocialPlatforms;

// And where is this instanced? MultiplayerController itself? public class MultiplayerController :MonoBehaviour {

 const int Maxopponent = 1;
 const int Minopponent = 1;
 //const int varient = 0;
 private const uint varient = 0xffffffff;
 public string IsActiveId;
 string invitationId=null;
 public static bool CanPlay = false;
 public string ParticipentID = null;
 public string Participent1ID = null;
 //Invitation mIncomingInvitation = null;
 private static MultiplayerController _instance = null;
 //public List <string> ParticipantIDs;
 public List<PlayPlatformController> mListPlayPlatform;
 public TurnBasedMatch GameMatched1; 
 public bool Success1;
 public PlayPlatformController mPlatform;
 public static int IncomingStatus = 0;
 public GameObject MenuUI;
 public GameObject TurnIn;
 public GameObject TurnOut;
 public Text testcase123;
 //Receive Invitation to be place for Callback further ...../
  Invitation wInvitation = null;
  TurnBasedMatch wTurnBased = null;
 public void Awake(){
     
 }
 public void Start(){
     PlayGamesPlatform.Instance.TurnBased.RegisterMatchDelegate (OnMatchReceive);
     PlayGamesPlatform.Instance.RegisterInvitationDelegate (OnInvitationReceive);
     DontDestroyOnLoad(this.gameObject);
     if (mPlatform != null) {
         mPlatform.Start ();
     }
 }

 public void Update(){
     if (mPlatform != null) {
         mPlatform.Update ();
     }
 /*    if (IncomingStatus == 0) {
     MenuUI.SetActive (true);
     }*/
     if (wInvitation != null) {
         ShowIncomingInvitationUI ();
     }

     if (wTurnBased != null) {
         ShowIncomingMatchUI ();    
     }
 }

 public void OnLevelWasLoaded(int level){
     if (level == 4) {
         GameEngine.Instance.SpawnRandomMarbles();
     }
     if (level == 3) {                           // for testing purpose 
         
         if (mPlatform != null) {
             mPlatform.OnLevelWasLoaded (level);
         }
     }
     if (level == 5) {
         if (mPlatform != null) {
             mPlatform.OnLevelWasLoaded (level);
         }
     }
 }
 public void MatchActive(){
     PlayGamesPlatform.Instance.TurnBased.CreateWithInvitationScreen (Minopponent, Maxopponent, varient, OnMatchStarted);
 }
 private void OnMatchStarted(bool success,TurnBasedMatch GameMatched){
 if (success) {
         mPlatform = new PlayPlatformController();
         mPlatform.LaunchGame (GameMatched);
     }
     else {
         Debug.Log ("Error");
     }
 }
 public bool IsAuthenticated() {
     return PlayGamesPlatform.Instance.localUser.authenticated;
 }
 public static MultiplayerController Instance {
     get {
         if (_instance == null) {
             _instance = new MultiplayerController();

         }
         return _instance;
     }
 }
 public void InvitationHandler(Invitation mInvitation,bool InvitationReceive){
     OnInvitationReceive (mInvitation, InvitationReceive);
 }
 public void OnInvitationReceive(Invitation mInvition ,bool OnReceive){                           ///Invitation Receive /// Notification not required 
     if (OnReceive) {
         PlayGamesPlatform.Instance.TurnBased.AcceptInvitation (mInvition.InvitationId, OnMatchStarted);
     }
     else {
         wInvitation = mInvition;

     }
 }
 public void OnMatchHandle(TurnBasedMatch mMatch,bool MatchReceive){                         
     OnMatchReceive (mMatch, MatchReceive);
 }
 public void OnMatchReceive(TurnBasedMatch mMatched, bool OnReceive){                         ///Match Invitation Notification Here Match Begins for player 2 ////                       
     if (OnReceive) {
         GameEngine.Base = new GameObject ("(Singleton)Base").AddComponent<Base> ();
         GameEngine.GameLogic = new GameObject ("(Singleton)GameLogic").AddComponent<GameLogic> ();
         GameEngine.Base.Load ();
         GameEngine.InMatchDel = true;                                                   ///Decide the turn of the Match either receive 
         OnMatchStarted (OnReceive, mMatched);
     }
     else {
         wTurnBased = mMatched;

     }
 }

/ public void SetUpObj(){ GameEngine.Base = new GameObject ("(Singleton)Base").AddComponent (); GameEngine.GameLogic = new GameObject ("(Singleton)GameLogic").AddComponent (); GameEngine.Base.Load (); GameEngine.InMatchDel = true; foreach (MatchData.BlockDesc mBLock in MatchData.mListBlockDesc) { GameEngine.mGameLog.MarbleNumber = mBLock.NumberOfMarbles; GameEngine.mGameLog.BackgroundIndex = mBLock.Background; GameEngine.mGameLog.GameType = mBLock.Gametype; } }/

 public void ShowIncomingInvitationUI(){
     MenuUI.SetActive (false);
     testcase123.text = "New Invitation receive";

 }
 public void ShowIncomingMatchUI(){
     MenuUI.SetActive (false);
     TurnBasedMatch newTurnBased = wTurnBased;
     switch (newTurnBased.TurnStatus) {
     case TurnBasedMatch.MatchTurnStatus.MyTurn:
         TurnIn.SetActive (true);
         break;
     default:
         break;
     }
 }

}