ASP.NET Core Seed

//  DbInitializer.Seed(serviceProvider.GetRequiredService<AppDbContext>());
//  IServiceProvider serviceProvider

using Microsoft.AspNetCore.Identity;
using Models;
using System;
using System.Linq;

namespace Data.Seed
{
    public class DbInitializer
    {
        private static string adminRoleId = "e8b6fc47-ad33-486e-ac87-37d639562e71";
        private static string userRoleId = "18b6fc47-ad33-486e-ac87-37d639562e71";
        private static string userId = "08b6fc47-ad33-486e-ac87-37d639562e71";

        public static void Seed(AppDbContext context)
        {
            if( !context.Roles.Any())
            {
                context.AddRange
                (
                    new IdentityRole { Id = adminRoleId, Name = "Administrator", NormalizedName = "Administrator".ToUpper() },
                    new IdentityRole { Id= userRoleId, Name = "User", NormalizedName = "User".ToUpper() }
                );
            }
            if (!context.Posts.Any())
            {
                context.AddRange
                (
                     new Post
                     {
                         Title = "New Post",
                         ImageUrl = "image",
                         Rating = 3,
                         CreatedAt = DateTime.UtcNow
                     }
                );
            }
            if (!context.Users.Any())
            {
                var user = new User
                {
                    Id = userId,
                    UserName = "[email protected]",
                    Email = "[email protected]",
                    SecurityStamp = string.Empty,
                };
                user.PasswordHash = PassGenerate(user);
                context.AddRange(user);
            }
            if (!context.UserRoles.Any())
            {
                context.AddRange
                (
                    new IdentityUserRole<string> { UserId = "08b6fc47-ad33-486e-ac87-37d639562e71", RoleId = "e8b6fc47-ad33-486e-ac87-37d639562e71" }
                );
            }
            context.SaveChanges();
        }

        public static string PassGenerate(User user)
        {
            var passHash = new PasswordHasher<User>();
            return passHash.HashPassword(user, "Administrator9#");
        }
    }
}