try
{
    string url = Constants.requestUrl + "Host=" + host + "&Database=" + database + "&Request=Fsq6Tr";
    string contentType = "application/json";
    JObject json = new JObject
    {
        { "CAF", caf },
        { "CustomerID", retailerCode },
        { "EmployeeNumber", employeeNumber },
        { "Street", street },
        { "Barangay", barangay },
        { "Town", town },
        { "District", district },
        { "Province", province },
        { "Country", country },
        { "Landmark", landmark },
        { "Telephone1", telephone1 },
        { "Telephone2", telephone2 },
        { "Mobile", mobile },
        { "Email", email },
        { "Location", location },
        { "Date", Convert.ToDateTime(date) },
        { "StartTime", Convert.ToDateTime(startTime) },
        { "EndTime", Convert.ToDateTime(endTime) },
        { "Photo1", photo1 },
        { "Photo2", photo2 },
        { "Photo3", photo3 },
        { "Video", video },
        { "MobilePhoto1", photo1url },
        { "MobilePhoto2", photo2url },
        { "MobilePhoto3", photo3url },
        { "MobileVideo", videourl },
        { "Rekorida", rekorida },
        { "Merchandizing", merchandizing },
        { "TradeCheck", tradecheck },
        { "Others", others },
        { "OtherConcern", otherconcern },
        { "Remarks", remarks },
        { "LastSync", Convert.ToDateTime(current_datetime) },
        { "MobileUpdate", Convert.ToDateTime(current_datetime) }
   };

   HttpClient client = new HttpClient();
   var response = await client.PostAsync(url, new StringContent(json.ToString(), Encoding.UTF8, contentType));

    await DisplayAlert("Success!", "Form sent successfully!", "Got it");
   }
   catch (Exception ex)
   {
         await DisplayAlert(" Sending Error ", ex.Message, "Got it");
   }