Lan on photon

Hello,

I just started with Unity and C# and js. And i want to create a Multiplayer game wich is going really good only when a player connects to a server i goes thru photon servers wich is oke for internet and for the server browser to work. but the thing is that i also want player to be able to connect with IP and only over LAN without the signal ever going to the internet. I searched online but i could not find a solution. could you please help me? here is a part of my NetWorkmanager script.

 //start een server
     private void StartServer(){
         Network.InitializeServer(4, 24000, !Network.HavePublicAddress());
         //4 is hoeveel players en 25000 is de port
         MasterServer.RegisterHost(typeName, gameName);
         Debug.Log("Server Started");
 
     }
 
     void OnServerInitialized()
     {
         Debug.Log("Server Initializied");
         SpawnPlayer();
         canvas.SetActive(false);
     }
     //knop
     void OnGUI()
     {
         if (!Network.isClient && !Network.isServer)
         {
             RefreshHostList();
             //moet worden veranderd naar dat hij elke seconde checkt want dit kost heel veel frames
             TextAway();
             if (GUI.Button(new Rect(100, 100, 250, 100), "Start Server"))
                 StartServer();
             //if (GUI.Button(new Rect(100, 250, 250, 100), "Refresh"))
             //    RefreshHostList();
             if (GUI.Button(new Rect(100, 250, 250, 100), "Quit"))
                 Application.Quit();
                 //joinIp("localhost:25000");
         
 
 
 
             
             if (hostList != null)
             {
                 for (int i = 0; i < hostList.Length; i++)
                 {
                     if (GUI.Button(new Rect(400, 100 + (110 * i), 300, 100), hostList[i].gameName))
                         JoinServer(hostList[i]);
                 }
             }
 
 
 
         }
     }
 
     void TextAway(){
         canvas.SetActive(true);
 
     }
 
         
 
         
     //check of er servers zijn
     private HostData[] hostList;
     
     private void RefreshHostList()
     {
         MasterServer.RequestHostList(typeName);
         Debug.Log("Refresh server list");
 
     }
     
     void OnMasterServerEvent(MasterServerEvent msEvent)
     {
         if (msEvent == MasterServerEvent.HostListReceived)
             hostList = MasterServer.PollHostList();
     }
     //join een server
     private void JoinServer(HostData hostData)
     {
         Debug.Log("connecting ...");
 
         Network.Connect(hostData);
     }
     
     void OnConnectedToServer()
     {
         Debug.Log("Server Joined");
         SpawnPlayer();
         canvas.SetActive(false);
     }
     //join ip
     void joinIp(string ip){
         Debug.Log("connecting to " + ip);
 
         Network.Connect(ip);
 
     }
     //spawn een player
     public GameObject playerPrefab;
     private void SpawnPlayer()
     {
         Network.Instantiate(playerPrefab, new Vector3(0f, 50f, 0f), Quaternion.identity, 0);
 
     }
 
 }

I also tried connecting to IP but then i get an error that the server is not connected to photon main server. Iam dutch so all the comments are also in dutch i hope its not a problem :). i can change it if you want.