Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
There are some on-going problems reported with the Office apps on an Apple Mac at the moment.
1
At the top left of your Mac desktop, click the Apple icon and select 'About this Mac', what version of MacOS is installed on your computer?
2
Log into your Microsoft account on this link, do you find your Office subscription listed there, and if so, check the expiry date listed on your subscription, is that listed correctly.
https://account.microsoft.com/services/
If not, go to the Billing section, is it indicated your subscription payment has been processed correctly.