class Program
    {
        static void Main(string[] args)
        {

            ArticleServiceClient client = new ArticleServiceClient();

            client.ClientCredentials.UserName.UserName = "логин"; // на самом деле там правильный логин
            client.ClientCredentials.UserName.Password = "пароль";

            PostingReadyForGiveoutListGetRequestBody req = new PostingReadyForGiveoutListGetRequestBody();
            req.request = new ozon.api.subagent.RequestPostingReadyForGiveoutListGet();
            req.request.Login = "логин";
            req.request.Password = "пароль";
            req.request.ContractID = 2394239929239; // contract ID


            PostingReadyForGiveoutListGetResponseBody res = new PostingReadyForGiveoutListGetResponseBody();
            res.PostingReadyForGiveoutListGetResult = client.PostingReadyForGiveoutListGet(req.request);

            Console.WriteLine(res.PostingReadyForGiveoutListGetResult.ResultMessage);

            client.Close();

            Console.ReadLine();
        }
    }