Check your email confirmation or the physical card inside the box if you bought a retail version. The 25-character key is required for initial setup at office.com/setup Retrieving a Key from Your Computer
Which of those would you like?
You can no longer buy Office 2019 directly from Microsoft as they have transitioned to Microsoft 365 Office 2024 microsoft office 2019 product key list exclusive
cscript "C:\Program Files\Microsoft Office\Office16\ospp.vbs" /dstatus Check your email confirmation or the physical card