Moving from Windows to MacOS - How to migrate licens?

[dbpusr]

Migrated from Windows to MacOS and now wondering how I either 1) migrate existing licens for Windows to MacOS or 2) how to use the upgrade offers for MacOS version since it doesn't allow for pick whether Windows or MacOS version? Please advice.

[Spoon]

The offer link is needed if using R17 or older. The latest version comes with both Windows and macOS.