Expo.io Push Notifications Send Through C#

Expo_Push_Notifications_Helper.cs

public class ExpoPushHelper
{
    public class MyWebClient : WebClient
    {
        protected override WebRequest GetWebRequest(Uri address)
        {
            HttpWebRequest request = base.GetWebRequest(address) as HttpWebRequest;
            request.AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip;
            return request;
        }
    }
    internal class UnderscoreContractResolver : DefaultContractResolver
    {
        protected override string ResolvePropertyName(string propertyName)
        {
            return Regex.Replace(propertyName, "(?<=[a-z])[A-Z]", m => "_" + m).ToLower();
        }
    }
    public class ExpoResponseData
    {
        public ExpoResponse Data { get; set; }
    }
    public class ExpoResponseBulkData
    {
        public List<ExpoResponse> Data { get; set; }
    }
    public class ExpoResponse
    {
        public string Status { get; set; }
        public string Message { get; set; }
        public DetailsError Details { get; set; }
    }
    public class DetailsError
    {
        public string Error { get; set; }
    }
    public static dynamic SendPushNotification(string ExpoToken)
    {
        dynamic body = new
        {
            to = ExpoToken,
            title = "hello",
            body = "world",
            sound = "default",
            data = new { some = "daaaata" }
        };
        string response = null;
        ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
        using (MyWebClient client = new MyWebClient())
        {
            client.Encoding = System.Text.Encoding.UTF8;
            client.Headers.Add("accept", "application/json");
            client.Headers.Add("accept-encoding", "gzip, deflate");
            client.Headers.Add("Content-Type", "application/json");
            response = client.UploadString("https://exp.host/--/api/v2/push/send", JsonExtensions.ToJson(body));
        }
        ExpoResponseData results = JsonConvert.DeserializeObject<ExpoResponseData>(response,
         new JsonSerializerSettings { ContractResolver = new UnderscoreContractResolver() });
        if (results.Data.Status.ToLower() == "ok")
            return "ok";
        else if (response.ToLower().Contains("devicenotregistered"))
        {
            //remove this key in your DB
            //await DeleteRegistrationExpoAsync(expoToken);
        }  
        else if (response.ToLower().Contains("unable to retrieve the fcm server key"))
        {
            //await DeleteRegistrationExpoAsync(expoToken);
            return "FCM server key error, removing";
        }
        return response;

    }
}