If your engineering workstation must remain air-gapped (offline), you can use a separate machine to log into the official NI Activation portal. By inputting your Product Serial Number and your unique (found via the NI License Manager), NI generates a secure alphanumeric activation code specifically tied to that offline machine. License Manager Download - NI
For a secure and legal alternative, NI offers a Community Edition of LabVIEW which is free for personal, non-commercial use. Deep Learning Toolkit for LabVIEW Download - NI Ni License Activator 1.3