SitecoreController.cs

namespace XXXX.Controllers
{
    using Microsoft.AspNetCore.Mvc;
    using Sitecore.AspNet.RenderingEngine;
    using Sitecore.LayoutService.Client.Exceptions;
    public class SitecoreController : Controller
    {
        public IActionResult Index()
        {
            var request = HttpContext.GetSitecoreRenderingContext();
            if (request == null || request.Response == null)
            {
                return new EmptyResult();
            }

			//Check if layout service call return any error
            if (request.Response.HasErrors)
            {
				//loop through errors
                foreach (var error in request.Response.Errors)
                {
                    switch (error)
                    {
						//this is the case of 404 errors
                        case ItemNotFoundSitecoreLayoutServiceClientException _:
                            Response.Redirect("/404");
                            break;
                    }
                }
            }

            return View();
        }
    }
}