I think if you go into the store and put ‘educational’ versions into the cart it should give you the methods to apply for the code when you attempt to check out.
It’s been a while since I used that site, but I remember things were grey and I could not do the last step in the check-out process until they gave me a special link…
Ever since I’ve been able to access that store and get the educational versions.
Try that site one more time. If you see that you can put educational versions into the shopping cart, then do it and follow through with the checkout process. At some point it should stop the process and request your validation.
Note, if it is marked as an Educational edition, then it already has the discount applied.
I did go look at my old emails, so if fiddling around with the website doesn’t get you access to at least put Educational Versions in your shopping cart, try sending your validation information to: firstname.lastname@example.org
More than a year ago, that’s where I sent mine. A day later they responded with approval. In their email was a special url ‘link’ that unlocked the store for me. Of course it might all be different now, but that was how it worked for me.