How do I page from PagedList.Mvc in NuGet?

using PagedList;

namespace FilteringPagingSorting.Controllers
{
    public class HomeController : Controller
    {
        private testContext db = new testContext();
        public ActionResult Index(int? page)
        {
            int pageSize = 3;
            int pageNumber = (page ?? 1);
            return View(db.Data1.ToPagedList(pageNumber, pageSize));
        }
    }
}

An exception of type 'System.NotSupportedException' occurred in EntityFramework.SqlServer.dll but was not handled in user code

Additional information: The method 'Skip' is only supported for sorted input in LINQ to Entities. The method 'OrderBy' must be called before the method 'Skip'.