TcpClient works

Client.cs

private TcpClient client = new TcpClient();

public async Task<string> ConnectSendReceive(string message, int port)
{
  Connect(port);
  await Write(message);
  string response = await Read();
  client.Close();
  
  return response;
}

private void Connect(int port)
{
  client.Connect(new IPEndPoint(IPAddress.Loopback, port));
}

private async Task<string> Read()
{
  var stream = client.GetStream();
  byte[] receiveBuffer = new byte[2048];
  int length = await stream.ReadAsync(receiveBuffer, 0, receiveBuffer.Length);
  return Encoding.Default.GetString(receiveBuffer, 0, length);  
}

private async Task Write(string message)
{
  var stream = client.GetStream();  
  byte[] byteMessage = Encoding.Default.GetBytes(message);
  await stream.WriteAsync(byteMessage, 0, byteMessage.Length);      
}