Microsoft Office 2019 Product Key List ((link)) -

Websites that host these "key lists" are rarely doing so out of charity. They are monetizing traffic.

If a key seems too cheap (e.g., $10 for Office 2019 Pro Plus), it’s likely a MAK (Multiple Activation Key) from an enterprise or a pirated key generator — Microsoft can and will deactivate it. microsoft office 2019 product key list