How to use a product key for Windows 2016 to activate 2012 R2?

Hello, we bought Server 2016 Standard from HP for a server that is restricted by the database software to Windows 2012 R2, because Microsoft licensing states that a valid product license for Windows is always valid for any previous version at the same (or lower in some cases) edition. This is based on …

Windows 2008 VPS via How to use a product key for Windows 2016 to activate 2012 R2?.