Authorization in .Net Framework 4.8 returns Unauthorized using OpenIdentity4 - rest

Question

I'm trying to use Authorization in .Net Framework 4.8, but making a get request returns Unauthorized using OpenIdentity4
I have to use Framework and not Core!
This is my Startup.cs:
public void Configuration(IAppBuilder app)
{
var authority = "https://localhost:5001";
var configurationManager = new ConfigurationManager<OpenIdConnectConfiguration>(
authority + "/.well-known/openid-configuration",
new OpenIdConnectConfigurationRetriever(),
new HttpDocumentRetriever());
var discoveryDocument = Task.Run(() => configurationManager.GetConfigurationAsync()).GetAwaiter().GetResult();
System.Console.WriteLine(discoveryDocument.AuthorizationEndpoint);
app.UseJwtBearerAuthentication(
new JwtBearerAuthenticationOptions
{
AuthenticationMode = AuthenticationMode.Active,
TokenValidationParameters = new TokenValidationParameters()
{
ValidateAudience = false,
}
}) ;
var config = new HttpConfiguration();
config.MapHttpAttributeRoutes();
config.Routes.MapHttpRoute(
name: "RestAPI",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = RouteParameter.Optional }
);
config.Formatters.Remove(config.Formatters.XmlFormatter);
config.Formatters.JsonFormatter.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
config.Formatters.JsonFormatter.SerializerSettings.DateTimeZoneHandling = Newtonsoft.Json.DateTimeZoneHandling.Utc;
app.UseWebApi(config);
}
}
}
OpenIdentity4 is running on https://localhost:5001
It's Startup:
public class Startup
{
public IWebHostEnvironment Environment { get; }
public Startup(IWebHostEnvironment environment)
{
Environment = environment;
}
public void ConfigureServices(IServiceCollection services)
{
var builder = services.AddIdentityServer()
.AddDeveloperSigningCredential()
.AddInMemoryApiScopes(Config.ApiScopes)
.AddInMemoryClients(Config.Clients);
services.AddControllers();
services.AddAuthorization(options =>
{
options.AddPolicy("ApiScope", policy => {
policy.RequireAuthenticatedUser();
policy.RequireClaim("RestAPI", "APIRest");
});
});
}
public void Configure(IApplicationBuilder app)
{
if (Environment.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
// uncomment if you want to add MVC
//app.UseStaticFiles();
//app.UseRouting();
app.UseIdentityServer();
app.UseRouting();
// uncomment, if you want to add MVC
app.UseAuthorization();
//app.UseEndpoints(endpoints =>
//{
// endpoints.MapDefaultControllerRoute();
//});
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers()
.RequireAuthorization("ApiScope");
});
}
}
}
It's probably a stupid mistake, but I can't figure it out.