To retrieve your Windows product key via Command Prompt (the "ask admin" method), use the following text/command:
(Get-WmiObject -query 'select * from SoftwareLicensingService').OA3xOriginalProductKey Physical "Top" Locations askadmin product key top
If the command doesn't return a result, your license might be stored differently: Physical Stickers : Look for a Certificate of Authenticity (COA) To retrieve your Windows product key via Command