Adorn Handbags - where do you put the promotional code to get your discount?

I am trying to order an Adorn bag - on line, and I wonder if anyone could tell me where on the Adorn order page I should put the promotional code, Tu Diabetes?

This is rather urgent as I only have a few more days left in the US and would like to order one to come to the address that I am staying at. Thanking anyone in advance.