Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
1
Open Word.
Click Word in the top menu beside the Apple icon.
Choose 'About Microsoft Word' from the drop-down menu.
On there you should see the Email address of the Microsoft account used for the subscription, then log into this link with that Microsoft account, are you able to find the subscription.
https://account.microsoft.com/services/
2
If not, did you start the subscription through the Apple App Store, if so you would need to contact Apple Support to cancel the subscription using the steps on this link.
https://support.apple.com/118428
3
If you are still unable to cancel the subscription or find the associated account, if you are being charged for the subscription, are you able to use the steps on this link to find the subscription.