Unable to download Microsoft 365 on macOS Monterey 12.7.6 for OneDrive document editing

Microsoft has a policy of supporting only the most recent three versions of macOS. You can supposedly continue to use existing copies of Office 365 for Monterey – without receiving any updates, but it's not entirely clear to me what would happen if you had to do a "clean reinstall."

Would you still be able to use the applications, or would you be blocked, just like anyone else trying to install 365, for the first time, on Monterey?

Microsoft Support – Upgrade macOS to continue receiving Microsoft 365 and Office for Mac updates

If you have been paying for a Microsoft 365 subscription, but have not already downloaded and installed 365, you might therefore be stuck between a rock and a hard place.

You could consider installing an alternative office suite like LibreOffice. The current version of that will run even on Catalina. It's free (although the developers would be happy to accept donations).

If you do not have Microsoft 365 installed on Monterey, and therefore, without further updates from Microsoft, then you cannot install it. Microsoft will block that installation on a now unsupported operating system.

You may however, be able to use Microsoft's free web version of Microsoft 365 after signing into your Microsoft account. That should still give you access to your documents on OneDrive.

LibreOffice, though free, and a clone of Microsoft Office, will not give you access to OneDrive. LibreOffice is a different interface and has a learning curve that you may not wish to travel.