Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Thanks Scott..
Unfortunately I don't have good news for you, unless your device hardware supports OS upgrade to at least 12 or above.
When macOS is below 12, Office products will now enter reduced functionality mode. In other words, the OS is too old to receive the licensing update the Office now requires. Sorry.
This is an update that occured on July 13th and Microsoft shared it here: https://support.microsoft.com/office/update-microsoft-365-or-office-on-your-macos-or-ios-device-f418ae5d-bb5f-4078-b3d9-9340f5dd084e
Your options will be: Use the web version or an alternative like LibreOffice. And you want to cancel your subscriptions.