Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Hi @Stefanie
Welcome to Q&A forum ~
Now Office for Mac supported by Microsoft includes Microsoft 365 for Mac, Office 2021 for Mac, and Office 2019 for Mac, but they supports the three most recent versions of Apple's macOS.
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In my opinion, I would suggest you choose on between Microsoft 365 for Mac and Office 2021 for Mac. For more details, you can check out this references "What's the difference between Microsoft 365 and Office 2021?".
But you can revert those 3 versions above to Office 2016 for Mac 15.xx versions to be compatible with your MacOS version.
To install older versions of Office for mac, here is an article "How to go back to Office 2016 for Mac 15.xx versions from 16.xx".
Besides, you can download installation file for a test.
Hope the information is helpful to you.
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