How to Install Microsoft SQL Server on Ubuntu 20.04

I created a Microsoft SQL Express server for my wife on Ubuntu 20.04.   I added ASP.Net to one of the Web Servers for her projects.

1> select @@version
2> go

Microsoft SQL Server 2019 (RTM-CU8-GDR) (KB4583459) – 15.0.4083.2 (X64)
Nov 2 2020 18:35:09
Copyright (C) 2019 Microsoft Corporation
Express Edition (64-bit) on Linux (Ubuntu 20.04.2 LTS) <X64>