In the Windows Search Bar type in “Activation settings” and hit enter. This will load the activation window showing which Windows 11 Edition you have installed and its activation status.
Under the “Change product key” row, click the “Change” button.
A window will open asking you to “Enter a product key“, type or paste in your 25 character Windows 11 key and click “Next“.
Back on the Activation window, your Windows Edition and activation status will update to reflect.