Unless I missed it, that sales policy that sberman referenced for you, it doesn’t spell out how to prove your eligibility. Nowhere that I can see does it state that you must provide some sort of proof that you are or will be an eligible student at a university or graduate school.
I’m going back 16 years, but when my son entered college, I believe that he had to provide some documentation that he was going to be attending school. I believe that you will need to provide an acceptance letter or a student ID as proof of eligibility. Otherwise, we could all claim that we are student, teachers or PTA members to get the discounts.
One way to know for sure would be to start an education discount order online and see what you need as proof. I assume that would tell you.