When I install generators for Yeoman, I usually go like this.
npm install --global generator-aspnet
Nice thing on the open source stuff is you can see access the source code.
using System.Web; using System.Web.Mvc;
Which tells us, it's a generator for the legacy ASP.NET MVC (up to MVC 5), because the
System.Web.* namespaces have been completely removed from ASP.NET Core, since they had a tight coupling to IIS which would prevented ASP.NET Core to become portable and run w/o IIS.