Microsoft 365 on older Mac version

Blodds wrote:

Hello - I have a Mac version 10.12.16. I have just purchased office 365 and now cannot install because I need version 10.14.0 or later. I have no updates available - can you help?

See if you qualify to update your macOS...

The older macOS installer backups on this server:

https://support.apple.com/en-us/HT211683

verify you are using the Safari browser to download/initiate the macOS links.

Sorry, you’ll have to contact Microsoft with that question. Are you sure you can’t update macOS further? What is the year and model of your MacBook?