Adisyonu XML Olarak Gönderir

var client = new RestClient("https://apitest.nilvera.com/ebill/Send/Xml");
client.Timeout = -1;
var request = new RestRequest(Method.POST);
request.AddHeader("Authorization", "<API KEY>");
request.AlwaysMultipartFormData = true;
IRestResponse response = client.Execute(request);
Console.WriteLine(response.Content);