Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
1
If this is a first time activation of Office, if you purchased Office from a 3rd party retailer, did you log into this web page to enter your product key to register the Office licence on your Microsoft account, and if any error is indicated, please provide a screenshot of the error.
https://setup.office.com/Home?wa=wsignin1.0
2
If this is not a first time activation of Office, if you log into your Microsoft account on this link, do you find your Office licence or subscription listed there?