A family of Microsoft word processing software products for creating web, email, and print documents.
I’m sorry to hear that you’re experiencing this issue. I’m happy to help.
Using the Microsoft account that was used for the purchase, check if your license is active:
https://account.microsoft.com/billing/orders
Open PowerPoint, click your profile picture, then select Log out. Restart your Mac computer.
Log back in using the account with the active license and check if the problem is now fixed.