How do I keep a client socket connection open and send/receive multiple messages in a console app

I am connecting to a server via TCP socket and sending in strings of data and expecting responses. The responses are unique to the request string and there are two responses per request. One that says the server completed an intermediate task and another indicating the task is complete. These tasks take up to about 20 seconds to complete. Note - I have no access to the server program/code its proprietary.

The client should be able to send in string requests anytime and sometimes fairly quickly. Requests could stack up and the client needs to wait for the unique responses to each request as they are received.

Assuming this needs an asynchronous client I am using the example right from the MS site.

https://docs.microsoft.com/en-us/dotnet/framework/network-programming/asynchronous-client-socket-example

Developing in a console app, I am able to connect and send string requests and I get one response back. The program then exits. New to async sockets I'm not sure how to keep the socket "alive" or open and randomly Console.Read new strings, send them, and get both responses as they are received.

Here is my client code.

public static Socket ClientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

// State object for receiving data from remote device.  
public class StateObject
{
    // Client socket.  
    public Socket workSocket = null;
    // Size of receive buffer.  
    public const int BufferSize = 256;
    // Receive buffer.  
    public byte[] buffer = new byte[BufferSize];
    // Received data string.  
    public StringBuilder sb = new StringBuilder();
}

public class AsynchronousClient
{

    // ManualResetEvent instances signal completion.  
    private static ManualResetEvent connectDone =
        new ManualResetEvent(false);
    private static ManualResetEvent sendDone =
        new ManualResetEvent(false);
    private static ManualResetEvent receiveDone =
        new ManualResetEvent(false);

    // The response from the remote device.  
    private static String response = String.Empty;

    public static void StartClient()
    {
        // Connect to a remote device.  
        try
        {
            IPEndPoint remoteEP = new IPEndPoint(ip, port);

            // Create a TCP/IP socket.  
            Socket client = new Socket(ip.AddressFamily,
                SocketType.Stream, ProtocolType.Tcp);

            // Connect to the remote endpoint.  
            client.BeginConnect(remoteEP,
                new AsyncCallback(ConnectCallback), client);
            connectDone.WaitOne();

            Console.WriteLine("Enter a message string: \n");

            message = Console.ReadLine();

            // Send test data to the remote device.  
            Send(client, message + "\r\n");  // \r\n required for server to know end of string
            sendDone.WaitOne();

            // Receive the response from the remote device.  
            Receive(client);
            receiveDone.WaitOne();

            // Write the response to the console.  
            Console.WriteLine("Response received : {0}", response);

        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }
    }

    private static void ConnectCallback(IAsyncResult ar)
    {
        try
        {
            // Retrieve the socket from the state object.  
            Socket client = (Socket)ar.AsyncState;

            // Complete the connection.  
            client.EndConnect(ar);

            Console.WriteLine("Connected to:  {0}", client.RemoteEndPoint.ToString());

            // Signal that the connection has been made.  
            connectDone.Set();
        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }
    }

    private static void Receive(Socket client)
    {
        try
        {
            // Create the state object.  
            StateObject state = new StateObject();
            state.workSocket = client;

            // Begin receiving the data from the remote device.  
            client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, 
                new AsyncCallback(ReceiveCallback), state);

        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }
    }

    private static void ReceiveCallback(IAsyncResult ar)
    {
        try
        {
            // Retrieve the state object and the client socket
            // from the asynchronous state object.  
            StateObject state = (StateObject)ar.AsyncState;
            Socket client = state.workSocket;

            // Read data from the remote device.  
            int bytesRead = client.EndReceive(ar);

            if (bytesRead > 0)
            {
                // There might be more data, so store the data received so far.  
                state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead));

                // Get the rest of the data.  
                client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                    new AsyncCallback(ReceiveCallback), state);
            }
            else
            {
                // All the data has arrived; put it in response.  
                if (state.sb.Length > 1)
                {
                    response = state.sb.ToString();
                }
                // Signal that all bytes have been received.  
                receiveDone.Set();
            }

            // Added this here to see if receiving would continue, does not work
            client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, 
                new AsyncCallback(ReceiveCallback), state);

        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }
    }

    private static void Send(Socket client, String data)
    {
        // Convert the string data to byte data using ASCII encoding.  
        byte[] byteData = Encoding.ASCII.GetBytes(data);

        // Begin sending the data to the remote device.  
        client.BeginSend(byteData, 0, byteData.Length, 0, new AsyncCallback(SendCallback), client);

    }

    private static void SendCallback(IAsyncResult ar)
    {
        try
        {
            // Retrieve the socket from the state object.  
            Socket client = (Socket)ar.AsyncState;

            // Complete sending the data to the remote device.  
            int bytesSent = client.EndSend(ar);
            Console.WriteLine("Sent {0} bytes to server.", bytesSent);

            // Signal that all bytes have been sent.  
            sendDone.Set();

        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }
    }

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