$.ajax({
        url: '/Home/Index',
        type: 'POST',
        data: JSON.stringify(Model), // This is all you have to change
        contentType: "application/json",
        cache: false,//
        success: function (dat) {
            if (dat.status === true) {
                OpenModalOk();


            } else {
                $('#esito').html('<b>' + dat.Message + '</b>');
                OpenModalFalse(dat.Message);
                console.log(dat.Message);
            }
        },
        error: function (dat) {
            console.log(dat.Message);

        }
    });

  [HttpPost]
        public async Task<ActionResult> Index(CustomerSettingsViewModel Model)
        {

             .....
            //dopo una serie di controlli l'invio al CORE 

 var requestor = new CustomerSettingsViewModel();
            requestor.CustomerData = Model.CustomerData;
            requestor.Setting = Set;

            JsonSerializerSettings settings = new JsonSerializerSettings();
            settings.ContractResolver = new CamelCasePropertyNamesContractResolver();
            var myJson = JsonConvert.SerializeObject(requestor, settings);

            //   var myJson = JsonConvert.SerializeObject(CustomerData);

            var httpContent = new StringContent(myJson, Encoding.UTF8, "application/json");

            using (var httpClient = new HttpClient())
            {

                // Do the actual request and await the response
                var httpResponse = await httpClient.PostAsync("https://localhost:44358/api/Subscription/InsertFromWeb", httpContent);

                if (httpResponse.Content != null)
                {
                    var responseContent = await httpResponse.Content.ReadAsStringAsync();

$("#submitEN").click(function () {
$("#submitIT").click(function () {

 $("#submitEN").off().on('click', function () {

 $("#submitIT").off().on('click', function () {