string aa = System.Net.NetworkInformation.NetworkInterface.GetAllNetworkInterfaces()
.Select(p => p.GetIPProperties())
.SelectMany(p => p.UnicastAddresses)
.Where(p => p.Address.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork && !System.Net.IPAddress.IsLoopback(p.Address))
.FirstOrDefault()?.Address.ToString();