Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
There are a couple of on-going problems with the Office apps on an Apple Mac at the moment, this is caused by an update released on 13 July and after that update, the old workaround to install an older version of Office no longer works.
At the top left of your Desktop, click the Apple icon and select 'About this Mac', what version of MacOS is installed on your computer?