When you start your online order make sure that Linda Bartolucci is listed as your demonstrator.  At any time when you view your shopping bag you will see a screen like the one below.  Just enter your hostess code in the space at the bottom of your shopping bag.  Be sure to click APPLY to make it stick to your order.

Please remember if your order is $150 or more you do not want to use the code because you would be giving up Hostess Benefits.