Be able to find the NuGget package to install from https://docs.microsoft.com/en-us/dotnet/api

I'm trying to build a console project (.NetCore 3.1) to run the matrix multiplication example.

The issue is the following with VS2109

• using System.Windows.Media; (VS2019 suggest me to remove the ".Media")

Just by looking at the Microsoft documentation on the web, can you explain how can I find the package to use.