An example of registering an Authentication middleware in .NET Core

AuthenticationStartup.cs

public class Startup
{
    public IConfiguration Configuration { get; }
    
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }
    
    public void ConfigureServices(IServiceCollection services)
    {
        // Read Auth0 settings from configuration
        var auth0Configuration = Configuration.GetSection("Auth0");
        var domain = auth0Configuration.GetValue<string>("Domain");
        var audience = auth0Configuration.GetValue<string>("Audience");
        // Add Authentication service
        services.AddAuthentication(
                options =>
                {
                    options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
                }
            )
            .AddJwtBearer(
                options =>
                {
                    // Configure Auth0 domain as authority
                    options.Authority = domain;
                    // Configure Auth0 API Identifier as audience
                    options.Audience = audience;
                }
            );
          // ... other service registration omitted for brevity
    }
    
    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        // Add Authentication middleware
        app.UseAuthentication();
        
        // ... other configuration omitted for brevity
    }
}