Below are instructions to resend the confirmation email to all registrants within a particular event 

Note: Emails may not be received by participants for up to 60 minutes
Note: If notification emails are configured on step 10 of event setup, participants will also receive this notification - we recommend turning off this notification (from step 10) before resending
  1. Click event name under Your events on Organization Dashboard (HOME)
  2. Click Participants tab
  3. Click Resend all confirmation emails
  4. Click OK