RestSharp

using System;
using RestSharp;
namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            var client = new RestClient("http://172.18.68.249/api");
            var request = new RestRequest("/login", Method.POST);
            request.AddHeader("Content-Type", "application/json");
            request.RequestFormat = DataFormat.Json;
            request.AddJsonBody(new { UserName = "Administrator", Password = "Welcome01_", Domain = "Test-domain" });

            IRestResponse response = client.Execute(request);
            Console.WriteLine((int)response.StatusCode);

            var request_list = new RestRequest("/tasks", Method.GET);
            request_list.RequestFormat = DataFormat.Json;
            request_list.AddCookie(".AspNetCore.Cookie", response.Cookies[0].Value);
            IRestResponse response1 = client.Execute(request_list);
            Console.WriteLine((int)response1.StatusCode);
        }
    }
}