RoomGameManager.cs

using UnityEngine;
using Mirror;
using kcp2k;
using System.IO;
using System;
using System.Collections.Generic;

public class RoomGameManager : MonoBehaviour
{
    [SerializeField]
    private ServerSocket _serverSocket;
    private NetworkManager _networkManager;
    private KcpTransport _transport;
    private string _logFilePath;    
    
    void Awake()
    {               
        Dictionary<string, string> arguments = new Dictionary<string, string>();                                                    
        // parsing arguments
        string[] args = System.Environment.GetCommandLineArgs();
        for (int i = 0; i < args.Length; i++)
        {                
            if (args[i].StartsWith("-"))
            {
                string key = args[i];
                string value = (i + 1 < args.Length && !args[i + 1].StartsWith("-")) ? args[i + 1] : null;
                arguments[key] = value;
            }
        }

        //Select network manager
        if (_networkManager == null)
            _networkManager = FindObjectOfType<NetworkManager>();
        if (_transport == null)
            _transport = FindObjectOfType<KcpTransport>();

        // Server automatically launched
        if (arguments.ContainsKey("-port"))
        {
            _logFilePath = Path.Combine(Application.persistentDataPath, "log.txt");
            Application.logMessageReceived += LogToFileHandler;

            using (StreamWriter writer = new StreamWriter(_logFilePath, true))
            {
                _transport.port = (ushort)int.Parse(arguments["-port"]);
                writer.WriteLine(DateTime.Now + ": Starting server on port: " + _transport.port);

                if (!_networkManager.isNetworkActive)
                {
                    _networkManager.StartServer();  // Start Mirror server
                    writer.WriteLine(DateTime.Now + ": Server started at port " + _transport.port);
                }

                // Start Communication Server
                _serverSocket.StartServer(_transport.port + 1);
            }
        }
        else // A client is connecting to the room
        {
            Debug.Log("Room loaded with port: " + RoomData.port + ", Name: " + RoomData.roomName);
            _transport.port = (ushort)RoomData.port;
            //_transport.port = 7780;
            _networkManager.StartClient(); // Start Mirror client            
        }
        
    }

    private void LogToFileHandler(string logString, string stackTrace, LogType type)
    {
        using (StreamWriter writer = new StreamWriter(_logFilePath, true))
        {
            writer.WriteLine($"{type}: {logString}");
            if (type == LogType.Error || type == LogType.Exception)
            {
                writer.WriteLine(stackTrace);
            }
        }
    }
    
}


public static class RoomData
{
    public static int port;
    public static string roomName;
}