I registered on site for conference and did not get a Registration ID at that time. How can I get one?

I registered on site for conference and did not get a Registration ID at that time. How can I get one?
February 5, 2018

Registration IDs can be found on attendee name tags which are distributed at check-in. In addition, Registration IDs will be emailed to the e-mail address on file for those who registered on site.