No home button / ribbon - can't colour code my emails

Hi, I have Outlook for Mac 16.61

I'd like to use colours to categorise my emails. Everything I read online says to go to the 'home' button and then 'categorize' then 'edit categories' however I don't have a home menu on my Outlook

I only have File, Edit, View, Message, Format, Tools, Window, Help. 

What am I missing?