I don’t not want to purchase Outlook after trial. How do I get rid of the prompt to do so every time I start up my Mac!

I purchased Microsoft Office online as a download.  I had no idea that Outlook was not included.  I do not want to purchase Outlook now that the trial period is over.  How do I get rid of the prompt to purchase it that pops up EVERY TIME I start up my Mac?  There is no option to not purchase it.  What a pain in the tush this is.  Please note, I do not have a PID number!  Please help if you can as I would appreciate it very much!