Dear mohamedhoma,
Thanks for reaching out! I'm an Independent Advisor and a Microsoft user like you. I will be happy to assist you in this regard.
Depending on how you got your copy of Windows 10, you'll need either a digital license or a 25-character product key to activate it. Without one of these, you won't be able to activate your device.
1-A digital license (called a digital entitlement in Windows 10, Version 1511) is a method of activation in Windows 10 that doesn't require you to enter a product key.
2-A product key is a 25-character code used to activate Windows. What you'll see is PRODUCT KEY: XXXXX-XXXXX-XXXXX-XXXXX-XXXXX.
May I know which Windows Edition Are you using?
Start > type winver > Hit Enter
You have to use an activation key that compatible with your Windows Edition.
Kindly check out the link below for more information:
https://support.microsoft.com/en-us/windows/act...
Please let me know if you need further assistance and keep me updated.