A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
1
The 'Repair Now' button on that error popup dialog only performs a quick repair of the Office apps and that rarely resolves the problem with the Office apps, the best option is to perform a full online repair of your Office installation.
Before performing this process, please log into your Microsoft account on this link (https://account.microsoft.com/services/) and check to ensure your Office licence or Microsoft 365 subscription is listed correctly on your account.
Open the Settings App (gear icon on your Start Menu)
Go to Apps - Installed Apps, then scroll down to find Microsoft Office
Select that and choose Modify - Online Repair
That should fix any issues with your Office Installation.
2
Your also mention at the top of Excel it indicates 'Unlicensed Product'.
If the online repair does not also resolve that problem.
Open Excel, then go to File - Account, please provide a screenshot of that window, and please hide your Email address in the screenshot.