ASP.NET2.0 MVC tag helper does not work in partial views

Hi, just a note I "started on empty project".

 

The intellesense does not work when typing asp and the tag does not work either in partial view I add @addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers in _ViewImport.cshtml in Views folder but still it does not work.

 

The code is just simply  asp-controller="Account" asp-action="Register" class="btn btn-default">Register but does not work.