Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Sorry to hear that you're having trouble with this situation. If you purchased your Microsoft 365 subscription through Apple, the subscription should normally be linked to the Microsoft account you used when activating it, but it won't appear until that association has been completed. Could you please confirm whether you have already opened a Microsoft 365 app (such as Word) and signed in with the Microsoft account you want to use on the same device you purchased it on?
If the subscription still doesn't appear there after almost a month, it may indicate that the Apple subscription was never linked to your Microsoft account, in which case Apple Support may need to review the purchase and account association, as it was purchased through them; they need to link the purchase to the proper account.