Change existing field on registration form

Community Participant

We are having a problem with students registering on Catalog with just their first name.  Then, of course, their certificate has just their first name.  For one of our courses, students have to present the certificate to a court, so it's important that it states their full name.

The existing name field in the registration form is just one box.  If there were two required boxes, one for the first and one for the last name, that would solve this problem.  Is it possible to do that using custom code?  I don't see an option for the registration form under customizations for the catalog (screenshot below), so where would we put it?

We currently have tried to address the problem by adding a user-defined field with the label "Have you provided your full legal name above?"