Hi, good day! I'm Nals and I'll be happy to assist you today.
Could you please confirm if you have already purchased a Windows 11 product key?
If you upgraded from a previous version of Windows to Windows 11 for free, or if your device came pre-installed with Windows 11, you likely have a digital license. In this case, Windows 11 should have activated automatically during setup. However, you can check your activation status by going to Start > Settings > System > Activation. (Or) If your Windows 11 isn't activated and you have a Microsoft account linked to it, you can simply sign in with that same account to reactivate.
If you purchased a separate product key for Windows 11, you can activate it by following these steps:
Press Start and select Settings.
Go to System > Activation.
Click Change product key and enter your 25-character product key
Regards,
Nals