Hi Lindsay,
Within Express, there currently is not a data tag to allow registrants to print their own badge/ticket. However, on their Confirmation page once they complete registration there is a "Print Tickets" widget that they can utilize.
In addition, you do have the ability to include a QR Code data tag in an email which will have the registrant's Confirmation Number included.
Please let me know if you have further questions on this!
Best,
Danni