Hi Alex0021,
I’m Jung one of the Independent Advisor and I’d be happy to help you out with your question.
In order for you to have an access to all the features with in the Office program you may need to have an active office subscription or perpetual license. You may check your account if it has an office license associated to it through account.microsoft.com/services if you able to find that there's an active office license/subscription all you need to do is to login your account to the office apps or reinstall the office programs to refresh the function.
Here's the steps on how to Uninstall and Reinstall Office program.
Uninstall Office from a PC: https://support.microsoft.com/en-us/office/uninstall-office-from-a-pc-9dd49b83-264a-477a-8fcc-2fdf5dbf61d8?ui=en-us&rs=en-us&ad=us
Download and install or reinstall Office 365/Office 2016 or Office 2019 on a PC or Mac: https://support.microsoft.com/en-us/office/download-and-install-or-reinstall-microsoft-365-or-office-2021-on-a-pc-or-mac-4414eaaf-0478-48be-9c42-23adc4716658?ui=en-us&rs=en-us&ad=us
If the office subscription or license is not available on your account you might end up purchasing a Microsoft Office License or you can access the Office for free through web which it only has a limited feature and still its a free service. Kindly check this link: https://www.microsoft.com/en-us/microsoft-365/free-office-online-for-the-web
I hope this information helps. If you have any questions, please let me know and I’ll be glad to assist you further.
Best regards,
Jung