Registering the custom IFeatureFilter implementation

Startup.cs

namespace MusicStore.Web
{
    public class Startup
    {
        ... 
        
        public void ConfigureServices(IServiceCollection services)
        {
            ... 
            
            // Register the required IHttpContextAccessor
            services.TryAddSingleton<IHttpContextAccessor, HttpContextAccessor>();

            // Configure Feature Management
            services
                .AddFeatureManagement()
                .AddFeatureFilter<BrowserFilter>();

            ...
        }
    }
}