One method is to enter 'wmic path SoftwareLicensingService get OA3xOriginalProductKey' in Command Prompt This article explains a few different ways for how to find a Windows 10 product key.

To find your Windows 11 OEM product key, open Command Prompt or PowerShell as administrator, then enter: wmic path ...

For volume licenses, where one copy of the application is installed on multiple machines, the product key must be obtained from the vendor. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other ...