I only got a 7 day license, I’ve contacted seed4.me to change it.
Answering the questions above –
The promo code box is on the page you get up when you register an account with seed4.me, enter your email address and password on the left-hand side and the box for the promo code was on the right hand side of the page in my browser.
The promo code appears on the page after you have supplied your details to SOS. At the top of this page you get the links for the various downloads available, a few paragraphs below is where the promo code is.