System.Net.Http.HttpRequestException Connection Refused' Xamarin

Question

I have my API that is running correctly, then I have my application in which I have:

public partial class MainPage : ContentPage
    {
        HttpClientHandler insecureHandler;
        HttpClient client;
        Uri uri = new Uri("http://172.20.10.2:3000/api/operatori/getoperatori");
        public MainPage()
        {
            InitializeComponent();
            insecureHandler = GetInsecureHandler();
            client = new HttpClient(insecureHandler);
            client.Timeout = TimeSpan.FromSeconds(200); // this is double the default
        }

        async void Button_Clicked(object sender, EventArgs e)
        {
            bool login = false;
            try
            {
                Task<String> result = getOperation();
                string result2 = await result;
                var Item = JsonConvert.DeserializeObject<List<Operatore>>(result2);
                foreach (Operatore o in Item)
                {
                    if (o.oP_NOME == user.Text && o.oP_PASSWD == pass.Text)
                    {
                        login = true;
                    }
                }
            }
            catch (Exception ex)
            {
                welcome.Text += ex.ToString();
            }
            if (login == true)
            {
                await Navigation.PushAsync(new HomePage(user.Text));
            }
            else
            {
                await DisplayAlert("Login fallito!", "Username o Password Errati", "OK");
            }
        }

        private async Task<String> getOperation()
        {
            HttpResponseMessage response = await client.GetAsync(uri).ConfigureAwait(false);
            response.EnsureSuccessStatusCode();
            var risposta = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
            return risposta;
        }



        public HttpClientHandler GetInsecureHandler()
        {
            HttpClientHandler handler = new HttpClientHandler();
            handler.ServerCertificateCustomValidationCallback = (message, cert, chain, errors) =>
            {
                if (cert.Issuer.Equals("CN=localhost"))
                    return true;
                return errors == System.Net.Security.SslPolicyErrors.None;
            };
            return handler;
        }
    }

172.20.10.2 is my IP address. If I launch Google Chrome on my PC (where API is running) it work, but when I try yo make this HTTP request on my Android device (not emulator) I have this error: System.Net.Http.HttpRequestException Connection refused ---> System.Net.Sockets.SocketException: Connection refused

Even if I make the request from Chrome browser on phone, I have the same error.

Can I solve it?