End of support for Office 2016 and Office 2019 | Microsoft Support
: After installation, you'll need to activate Office. If you're using a product key, you'll be prompted to enter it during the installation process. For volume licensing versions, you might use a Key Management Service (KMS) or Multiple Activation Key (MAK) for activation. microsoft office 2016 pro plus 16042661001 v link
Microsoft Office 2016 Professional Plus version 16.0.4266.1001 End of support for Office 2016 and Office
Legitimate Microsoft Office 2016 Pro Plus product keys follow strict patterns: microsoft office 2016 pro plus 16042661001 v link