Here are the steps required on the backend for "My Certificates" to work:
(1) Please edit the template of the certificate at Components >> ProDEP >> Certificates >> Edit Template.
(2) For event event, you will need to save the "PMI Event Number" and "Event PDUs" fields under Components >> ProDEP >> Certificates.
(3) Then, you will need to mark the attendees as "attended" since only attended users can receive the certificate. This is done under Components >> DT Register >> Records.