DBContext registration with design time factory and usage of extension method GetConnectionString

appsettings.json

{
  "ConnectionStrings": {
    "DefaultConnection": "Data Source=.\\SQLEXPRESS;Initial Catalog=OpenWeather;Persist Security Info=True;Integrated Security=true;"
  },
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },
  "AllowedHosts": "*",
  "OpenWeatherHttpClientOptions": {
    "Url": "https://api.openweathermap.org/data/2.5/",
    "Key" : "take a look to user secrets :X" 
  }
}

Startup.cs

using System;
using System.Text;
using BackgroundServices;
using BackgroundServices.HttpClients;
using BackgroundServices.Options;
using BL;
using DAL;
using DAL.Models.Identity;
using DAL.Query.Abstraction;
using DAL.Query.AllCity;
using DAL.Repositories;
using DAL.Repositories.Abstraction;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Design;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

namespace OpenWeather
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {

            // it register DBContext with scoped lifetime
            services.AddDbContext<OpenWeatherDbContext>(
                options => options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));

            //register all repositories with scoped lifetime => https://github.com/khellang/Scrutor
            services.Scan(a =>
                //all concrete repositories must be in same assembly
                a.FromAssemblyOf<CityRepository>()
                    .AddClasses(c => c.AssignableTo(typeof(IRepository<,>)))
                    .AsImplementedInterfaces()
                    .WithScopedLifetime()
            );
            
            //...
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            else
            {
                app.UseExceptionHandler("/Home/Error");
                // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
                app.UseHsts();
            }

            app.UseHttpsRedirection();
            app.UseStaticFiles();

            app.UseRouting();

            app.UseAuthentication();
            app.UseAuthorization();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllerRoute(
                    "default",
                    "{controller=Home}/{action=Index}/{id?}");
            });
        }
    }

    public class Factory : IDesignTimeDbContextFactory<OpenWeatherDbContext>
    {
        public OpenWeatherDbContext CreateDbContext(string[] args)
        {
            var contextOptionsBuilder = new DbContextOptionsBuilder<OpenWeatherDbContext>();
            contextOptionsBuilder.UseSqlServer(
                "Data Source=.\\SQLEXPRESS;Initial Catalog=OpenWeather;Persist Security Info=True;Integrated Security=true;");
            return new OpenWeatherDbContext(contextOptionsBuilder.Options);
        }
    }
}