Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
The quick repair option when clicking that 'Repair Now' button on that error dialog rarely resolves the problem.
1
The best option is to perform a full online repair of your Office installation.
Open the Settings App (gear icon on your Start Menu)
Go to Apps - Installed, then scroll down to find Microsoft 365 (Office).
Select that and choose Modify - Online Repair
That should fix any issues with your Office Installation.
2
If that does not resolve the problem, completely uninstall Microsoft 365 (Office), then restart your PC and go to your Microsoft account on this link to download and reinstall Office.