Core MVC - Ajax unobtrusive does not exist

In my Core MVC 2.2 project I added jQuery Unobtrusive Ajax (v: 3.2.6) via Nuget packages. First thing I noticed there was no local folder added for it in wwwroot/lib, also if try something simple like:

@using (Ajax.BeginForm( ... 

I get an error: CS0103 The name 'Ajax' does not exist in the current context

Please advise how to fix this.