You do not need the Windows Server 2019 product key to perform an in-place upgrade to Windows Server 2025, as long as the server is already properly activated. For the upgrade, you will need a valid product key for Windows Server 2025 to enter during the upgrade process. The existing 2019 key is not required unless you're doing a reinstallation or rollback. If you're unsure whether the 2019 license is genuine or properly activated, you can check the activation status (run slmgr /xpr
from the Command Prompt).
If the above response helps answer your question, remember to "Accept Answer" so that others in the community facing similar issues can easily find the solution. Your contribution is highly appreciated.
hth
Marcin