Download a flashing tool like (Windows) or BalenaEtcher (Cross-platform). Select your Zorin OS ISO and your USB drive in the tool.
This article explores how Zorin OS licensing works, why public "keys" do not exist, and how you can legally create a fully functional, portable Zorin OS drive. The Reality of "Zorin OS Pro Keys" zorin os pro key portable
You can plug this USB into almost any computer, boot from it, and access your personalized Pro environment. Download a flashing tool like (Windows) or BalenaEtcher
For personal use, does not use a traditional "key" that locks to a single machine. Instead, you receive a unique download link for the Pro ISO, and you are permitted to install it on multiple computers that you personally own. Portable Use and Licensing why public "keys" do not exist