Good day @I'm an companionship backbone of myself,
I noticed that your question was posted under For Education, so may I kindly reconfirm whether you are using a Microsoft 365 Education account provided by your school/organization or a personal Microsoft account? If you are using a school or organizational account, could you please let us know which Microsoft 365 license is assigned to your account? You can check this by signing in to https://portal.office.com/account/?ref=Harmony and navigating to the Subscriptions section.
Does the message appear in all Office applications (such as Word, Excel, and PowerPoint), or only in a specific application?
Also, are you able to sign in and use Office on the web (for example, Word Online or Excel Online) with the same account without encountering any licensing issues?
In the meantime, please try signing out of all Office applications and then signing back in using the account that you believe is assigned the appropriate Microsoft 365 license.
Additionally, since you mentioned receiving the message "Microsoft cannot verify the license for this product. You should repair the Office program by using Control Panel", you can try repairing your Office installation by following these steps: Control Panel > Programs > Programs and Features > Microsoft 365/Office > right-click it and select Change.

Then choose Quick Repair. If the issue persists, please proceed with Online Repair and follow the on-screen instructions to complete the process.
For more information: Repair an Office application
If there are any updates or additional findings, please let me know. I will be happy to continue assisting you.