Developers with Visual Studio subscriptions are granted keys for testing purposes.
Activating Office 2021 LTSC requires specific keys based on your organization's infrastructure. Microsoft provides three primary methods through Microsoft Learn : Overview of Office LTSC 2021 - Microsoft Learn office 2021 ltsc key
LTSC 2021 provides 5 years of mainstream support. It does not receive new features (like AI-driven Copilot). Developers with Visual Studio subscriptions are granted keys
These keys are typically obtained through: office 2021 ltsc key