Query postgres database from a SQL cell in a .NET Interactive Notebook

Background: In Visual Studio Code, I can do the following:

1. Install the .NET Interactive Notebooks extension.
2. Ctrl-P > .NET Interactive: Create new blank notebook Create as '.dib'
3. In a C# (.NET Interactive) cell, run
   #r "nuget:Microsoft.DotNet.Interactive.SqlServer,*-*" and
   #!connect mssql ...
4. In a SQL (.NET Interactive) cell, execute SQL queries against SQL Server.

Question: How can I do the same for a Postgres database?