Startup.cs

public void ConfigureServices(IServiceCollection services)
{
    services.AddMvcCore()
        .AddAuthorization()
        .AddJsonFormatters();

    services.AddAuthentication("Bearer")
        .AddIdentityServerAuthentication(options =>
        {
            options.Authority = "http://localhost:5000";
            options.RequireHttpsMetadata = false;
            options.ApiName = "Api1";
        });

    services.AddAuthorization(options => options.AddPolicy("Founder", policy => policy.RequireClaim("Employee", "Mosalla")));
}