extra letter of recommendation HELP

Just wondering how my extra letter of recommendation from a Harvard alum and past employee should be submitted/uploaded to admissions

At the very bottom of the page: https://college.harvard.edu/admissions/application-process/application-requirements

Are you sure this is a good idea? Were you deferred or is this an application for regular decision? How well does this person know you are is this letter being submitted only because the writer is an alumnus/a? Did you ask admissions if you are encouraged to do this? Generally additional information should only be submitted if it could have a major impact on the way you are viewed.