Hello
Typically you cannot extract the product key from an installed Windows., unless it is an OEM key embedded in the motherboard, there's powershell command you can run, but you cannot manually input an OEM key anyway that's embedded in the motherboard, so having the key is moot point.
Can you please type cmd in the search on the taskbar and hit enter to launch command prompt, then run the following command:
slmgr /dlv
Then share a screenshot please. I think it is important to determine what type of license you have first.. then can move on to what you need to find the key.