Insert data from form to subform

Insert data from form to subform

I have two forms,
  • Event;
  • Tickets.
On the SubForm(it's the Tickets Form) located on the Event Form, I'm able to add "Promoter ID" and "Tickets Sold", to keep track of all tickets sold by a promoter, which then updates the data on the Tickets database.

I have added row.Events_ID = input.Event_ID; to "On Add Row" to the SubForm on the events form, so I can also include the events ID, so I can produce proper reports.

But, no matter what I do, I can't populate the rows on the subForm with the Form's ID.

Does anyone have any idea why?