Add Students to Event

I need a way to add students to the event that purchase outside of woocommerce. We have students that register offline via PO or Invoice but I still need them to be added to the event and/or tickets on wordpress (I need them to get the Follow-up Emails that are scheduled for students of the Events). We are using Events Calendar Pro with the Event Tickets add-on. I’ve asked the question on the Event Tickets forum as well because I’m not sure which this falls under.