Upload it to the Grass Valley activation portal to receive an "Activation Response File."
If you are a professional editor, the best way to handle an offline machine isn't a sketchy key—it’s the version.
For those with legitimate serial keys who must remain offline: Install EDIUS on the offline machine.
Full support for PQ and HLG, allowing you to edit and export in high dynamic range.
If you are looking to upgrade or find the best pricing for a legitimate license, checking with authorized Grass Valley resellers is the only way to guarantee a "better" editing experience.