Student Account about to expire, how can I renew it?

Hello. About a year ago, I got a student account, and now it's about to expire, but I can't find a way to resend my school documents to renew it (because I am still a student). I searched the entire site and can't find it. Supposedly, they were going to notify me a month in advance so I could renew it, but I never received that notice or the link to renew it. Can you help, please? Thank you!!!!!