NetworkMigrationManager does not work with unet matchmaker

hi everybody , I have a question about host migration in unet . When executing the following code . it work only on lan game but does not work on unet matchmaker , whats problem? I understand that the following code is for the lan game. I tried to convert to matchmaking but i cant:( please help

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.Networking;
 using UnityEngine.Networking.NetworkSystem;
 
 public class host_migration : NetworkMigrationManager {
 
     public static host_migration Instance;
     private PeerInfoMessage m_NewHostInfo = new PeerInfoMessage();
     private NetworkManager networkmanager;
     private void Awake()
     {
         print("Migration Awake call....");
         if (Instance == null) Instance = this;
     }
 
      // called on client after the connection to host is lost. controls whether to switch Scenes
      protected override void OnClientDisconnectedFromHost(NetworkConnection conn,out SceneChangeOption sceneChange)
      {
 
         base.OnClientDisconnectedFromHost(conn, out sceneChange);
         print("OnClientDisconnectedFromHost");
         bool newhost;
         FindNewHost(out m_NewHostInfo, out newhost);
         print("New host :- " + newhost);
 
         if (newhost)
         {
             print("You become a new host at port :- " + NetworkManager.singleton.networkPort);
             BecomeNewHost(NetworkManager.singleton.networkPort);
         }
 
         else
         {
             Reset(this.oldServerConnectionId);
             waitingReconnectToNewHost = true;
             NetworkManager.singleton.networkAddress = m_NewHostInfo.address;
             NetworkManager.singleton.client.ReconnectToNewHost(m_NewHostInfo.address, NetworkManager.singleton.networkPort);
             print("You become a new client reconnect port -------> " + NetworkManager.singleton.networkPort);
             print("new server ip :- " + m_NewHostInfo.address);
         }
 
     }
  // called on host after the host is lost. host MUST change Scenes
      protected override void OnServerHostShutdown()
      {
         base.OnServerHostShutdown();
 
     }
  // called on new host (server) when a client from the old host re-connects a player
      protected override void OnServerReconnectPlayer(NetworkConnection newConnection,GameObject oldPlayer,int oldConnectionId,short playerControllerId)
      {
         base.OnServerReconnectPlayer(newConnection, oldPlayer, oldConnectionId, playerControllerId);
         ReconnectPlayerForConnection(newConnection, oldPlayer, oldConnectionId, playerControllerId);
     }
     protected override void OnServerReconnectPlayer(NetworkConnection newConnection, GameObject oldPlayer, int oldConnectionId, short playerControllerId, NetworkReader extraMessageReader)
     {
         base.OnServerReconnectPlayer(newConnection, oldPlayer, oldConnectionId, playerControllerId, extraMessageReader);
 
     }
     // called on new host (server) when a client from the old host re-connects a non-player GameObject
     protected override void OnServerReconnectObject(NetworkConnection newConnection,GameObject oldObject,int oldConnectionId)
      {
         base.OnServerReconnectObject(newConnection, oldObject, oldConnectionId);
         ReconnectObjectForConnection(newConnection, oldObject, oldConnectionId);
     }
  // called on both host and client when the set of peers is updated
      protected override void OnPeersUpdated(PeerListMessage peers)
      {
         base.OnPeersUpdated(peers);
     }
  // utility function called by the default UI on client after connection to host was lost, to pick a new host.
      public override bool FindNewHost(out PeerInfoMessage newHostInfo,out bool youAreNewHost)
      {
         print("FindNewHost");
         return base.FindNewHost(out newHostInfo, out youAreNewHost);
     }
  // called when the authority of a non-player GameObject changes
      protected override void OnAuthorityUpdated(GameObject go,int connectionId,bool authorityState)
      {
         base.OnAuthorityUpdated(go, connectionId, authorityState);
         print("OnAuthorityUpdated");
     }
 }