Hello, ........ VN
Thank you for reaching out Microsoft Community. My name is Kevin and I'm happy to help you. I totally understand your concern with regards to Microsoft Office package that you cannot get access. I do apologize for the inconvenience.
If the Office is asking for the product key, we have ways to get it. Please make sure that you have subscription plan for Microsoft Office 365.
If you purchased a retail version of Microsoft 365 that includes a product key card, the product key is printed on the card. It's usually located on the back of the card or inside the packaging.
If you purchased Microsoft 365 online, Microsoft may have sent you an email confirmation with your product key. Search your email inbox for any messages from Microsoft or the retailer you purchased from.
If ever that were not able to obtain your Product key, please contact Microsoft phone support of your local region to help us with it. Please visit this link: https://support.microsoft.com/office/4f615f2a-6bbd-fd69-6695-ae213d63eef0
Please let me know if these information answered the concern and helped us to resolve the issue. Give back to the Community. Help the next person who has this issue by indicating if this reply solved your problem. Click Yes or No below.
Kind regards,
Kevin