Educational accounts I've used in the past, are not authenticated with "over the verification limit". Please help.

Hello, I was using Figma well as an educational account until last year.
I'm trying to re-certify it because it's expired, but it says "Over the verification limit" and I can't authenticate it anymore.

I expect it to have expired because I couldn't check the email to re-authenticate.

I'm having a lot of hard time because collaboration is not possible. Please help me recertify it. If you tell me how, I'll proceed quickly

My educational email is gachonjun@gachon.ac.kr 

Thank you.