Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Hello
Can you go to https://account.live.com > Subscription, what's the subscription name? If it is Microsoft 365 Basic, then it doesn't come with apps, it is for OneDrive storage only (100GB). If you have personal or family plan, make sure it is still in active status.
If so, back to the apps, can you make sure you sign in using the correct account. Go to Files > Accounts > Update license, sign in, see if it makes any difference.