[.Net Core] Visual Studio for Mac Add Client Side Library

There is Client-Side Library under the Add when I right click the project on Visual Studio for Mac. So I searched on Google, and find this post LibMan support in Visual Studio for Mac. But I can't find the Library Manager addin in the extension manager. But I find the work around for this, according to this youtube video Adding Client Side Libraries for Admin Panel using Microsoft Libman:

• Install the lib manager CLI:
  dotnet tool install --global Microsoft.Web.LibraryManager.Cli

• Install any library you want, for example:
  libman install twitter-bootstrap@3.3.7