RestClient POST
SSL:
ServicePointManager.ServerCertificateValidationCallback += (sender, cert, chain, sslPolicyErrors) => true;
var client = new RestClient(apihost);
var request = new RestRequest(Method.POST);
request.AddFile("Img", image1, "Img1");
request.AddParameter("UserName", "PCK");
IRestResponse response = client.Execute(request);
return response.Content;