Tthese are the parameters that are passed to the POST method that returns a list of products.
var client = new RestClient(ConfigurationManager.AppSettings["ServidorWS"]);
var request = new RestRequest("/rest/product/get", Method.POST);
request.AddHeader("Content-Type", "application/json; charset=UTF-8");
string variable = "{'PetitionType':'3','PageNumber':'1','Parameter':'APPLE','Rows':'12'}";
var serializer = new JsonSerializer();
serializer.Serialize(variable);
request.AddBody(variable);
var response = client.Execute(request);
var contenido = response.Content;