Earlier quoted context omitted.
Do fan-club registration in person.
Run it like an airline, where your name is on the ticket and you don't get in unless it matches your ID. Either that or your ID is the ticket. Just bloop that big barcode on the back of your ID with your phone when you buy the admission, then let the guy bloop it again at the door when you go to the show. That would make some scenarios harder, like the trope about your boss handing you two extra tickets she can't use…
Namely, if you are aware of intergroup variability in ID-having rates, is choosing it anyways a conscious discriminatory choice?