Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hey there, Gavin Bilington
If you have Microsoft 365 installed on your device downstairs, please open a Microsoft 365 app on your computer (can be Word, Excel or PowerPoint).
From the main page, please click onto 'Account'
On the account page, you should see your product information page.
Mine is different because I have activated my Microsoft 365, whereas you should see an option to sign in to activate Office. Please can you sign in using your other account you have a Microsoft 365 subscription with.
This will activate Microsoft 365 for you and use one of your available product keys.
If you haven't got Microsoft 365 downloaded, or not the same Microsoft 365 you have purchased, please download it from your account page here: https://account.microsoft.com/services
You will see an option to install a desktop version of Microsoft 365 apps to your device.
Once you have done this, please activate it using your account using the method I have mentioned above.
Hope this helps,
Nathan