Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
I have (or had!) Office Home 2024. The message at the top of each application open window says "Activate Microsoft 365 to Create and Edit. Your Office 2019 license is not supported with this version of the application." The 2019 version was on my mac when I got the new one and I do a "transfer" from old to new computer and then load new software.
Have you ever had Office 2019 installed on your Mac, or or any other device? I'm wondering how that version is suddenly showing up...
If you see Office 2024 listed in your Microsoft account at https://account.microsoft.com/services or if you see it in the App Store (maybe you purchased via the App Store), then you should be able to reinstall. You should be able to download the correct release of Office from the update history page at https://learn.microsoft.com/en-us/officeupdates/update-history-office-for-mac .
Also/alternatively, the support article at https://support.microsoft.com/en-gb/office/how-to-remove-office-license-files-on-a-mac-b032c0f6-a431-4dad-83a9-6b727c03b193 may be relevant.