@kathleenkcu 

I see the trigger is either list or a segment so for this flow to trigger there have to be new people added to that list or segment so you need to check if new people were added to it after the flow is set live.. that is the only way this flow will work when new people are added to the list or segment after you set it live. (or if you back-populate it by clicking on the options and then adding the past profiles..)

Hi Bobi! Thanks for the answer. I very new here. How do you back populate it? so everyone in the segment I set up receives the email in the flow

@kathleenkcu 

When you open the flow go to manage flow and then add past profiles