How do I buy C3 at half price (apply C2 license)?

I had a C2 license and I remember that C3 had the first year at half price if you added your C2 license code. I saw this screen yesterday but now that I'm buying C3, I can't find the place to add my C2 discount.

Try going to this page...

construct.net/en/profile/my-discounts

Thank you, that's what I was looking for :)