Авторизация на web портале из c# приложения

Question

Первый запрос проходит, а второй нет. Что я упускаю???

    class Program
    {
        static void Main(string[] args)
        {
        var user = "user";
        var password = "password";
        var cookies = new CookieContainer();
        var proxy = new WebProxy("127.0.0.1:8888");




        var getRequest = new GetRequest()
        {
            Address = "https://wsdemo.laximo.ru/",
            AcceptLanguage = "en-US,en;q=0.7,ru;q=0.3",
            Accept = "text/html, application/xhtml+xml, image/jxr, */*",
            Host = "wsdemo.laximo.ru",
            KeepAlive = true,
            TurnOffProxy = true

        };


        var data = $"{{\"user%5Blogin%5D={WebUtility.UrlEncode(user)}&user%5Bpassword%5D={WebUtility.UrlEncode(password)}&user%5Bbackurl%5D=https%3A%2F%2Fwsdemo.laximo.ru%2Findex.php%3Ftask%3Dcatalogs\"}}";


        var postRequest = new PostRequest()
        {
            Data = data,
            Address = $"https://wsdemo.laximo.ru/index.php?task=login&view=login",
            Accept = "text/html, application/xhtml+xml, image/jxr, */*",
            Host = "wsdemo.laximo.ru",
            ContentType = "text/html; charset=UTF-8",
            Referer = "https://wsdemo.laximo.ru/index.php?task=catalogs",

            KeepAlive = true,
            Proxy = proxy
        };
        postRequest.AddHeader("Origin", "https://wsdemo.laximo.ru");



        postRequest.Run(ref cookies);


        getRequest = new GetRequest()
        {
            Address = $"https://wsdemo.laximo.ru/index.php?task=catalogs&auth=true",
            AcceptLanguage = "en-US,en;q=0.7,ru;q=0.3",
            Accept = "text/html, application/xhtml+xml, image/jxr, */*",
            Host = "wsdemo.laximo.ru",
            ContentType = "text/html; charset=UTF-8",
            KeepAlive = true,
            Referer = "https://wsdemo.laximo.ru/index.php?task=catalogs",
            Proxy = proxy

        };


        getRequest = new GetRequest()
        {
            Address = $"https://wsdemo.laximo.ru/index.php?task=catalogs&auth=true",
            Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9",
            Host = "wsdemo.laximo.ru",
            ContentType = "text/html; charset=UTF-8",
            KeepAlive = true,
            Referer = "https://wsdemo.laximo.ru/index.php?task=catalogs",
            Proxy = proxy
        };
        getRequest.Run(ref cookies);



     //   Config.Instance.AddLogInfo(getRequest.Response);
    }
}

}