Hi @JosephLace,
Welcome to the global Instructure community! it's great to have you here.
To answer your question, the pronoun choices available in Canvas are actually set by each school/institution, not something that is global. With that in mind, you'd need to make your pronoun request to your school/institution Canvas team. Usually the Canas team is in the eLearning, IT, or Digital Education areas, but if there is a general help/support desk they'd probably be able to route your request to the right person.
I hope this info helps!
-Chris
