[FeatureGate("chat")]
public class ChatController : Controller
{
      public IActionResult Index()
      {
          // do sth
      }
}

[FeatureGate("feature1", "feature2")]
public class ChatController : Controller
 {
        public IActionResult Index()
        {
            // do sth
        }
 }

  "FeatureManagement": {
    "feature1": true,
    "feature2": false
  },

public enum RequirementType
    {
        //
        // Summary:
        //     The enabled state will be attained if any feature in the set is enabled.
        Any = 0,
        //
        // Summary:
        //     The enabled state will be attained if all features in the set are enabled.
        All = 1
    }

 [FeatureGate(RequirementType.Any,"feature1", "feature2","feature3")]
 public class ChatController : Controller
 {
        public IActionResult Index()
        {
            // do sth
        }
 }

public class RedirectDisabledFeatureHandler : IDisabledFeaturesHandler
    {
        public Task HandleDisabledFeatures(IEnumerable<string> features, ActionExecutingContext context)
        {
            context.Result = new RedirectResult("url");
            return Task.CompletedTask;
        }
    }

  public void ConfigureServices(IServiceCollection services)
   {
            services.AddFeatureManagement().UseDisabledFeaturesHandler(new RedirectDisabledFeatureHandler()); ;
    }