Startup.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Microsoft.IdentityModel.Tokens;
using web_service.database;
using web_service.Repositories;

namespace web_service
{
    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)
        {
            // Configuration connection string
            string connectionString = Configuration["connectionString"];
            services.AddDbContext<WebServiceContext>(options => options.UseMySql(connectionString));

            // DI
            services.AddScoped<UserRepository, UserRepository>();
            services.AddScoped<AthleteRepository, AthleteRepository>();
            services.AddScoped<PeladaRepository, PeladaRepository>();
            services.AddScoped<SportRepository, SportRepository>();
            services.AddScoped<TeamRepository, TeamRepository>();

            // JWT Bearer Authentication

            services.AddAuthentication(authOptions =>
            {
                authOptions.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
                authOptions.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
            })
            .AddJwtBearer(jwtBearerOptions =>
            {
                jwtBearerOptions.RequireHttpsMetadata = false;
                jwtBearerOptions.SaveToken = true;

                var key = Encoding.ASCII.GetBytes(Secret.KEY);
                jwtBearerOptions.TokenValidationParameters = new TokenValidationParameters
                {
                    ValidateIssuerSigningKey = true,
                    IssuerSigningKey = new SymmetricSecurityKey(key),
                    ValidateIssuer = false,
                    ValidateAudience = false
                };
            });

            services.AddCors();
            services.AddControllers().AddNewtonsoftJson(jsonOpitons => {
                jsonOpitons.SerializerSettings.ReferenceLoopHandling =   
                                        Newtonsoft.Json.ReferenceLoopHandling.Ignore;
            });

        }

        // 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();
            }

            app.UseHttpsRedirection();

            app.UseRouting();

            app.UseCors(corsPolicy =>
            {
                corsPolicy.AllowAnyOrigin().AllowAnyMethod().AllowAnyHeader();
            });

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

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });
        }
    }
}