I don t want to show the coupon using the shortcode

Hi!
I would like to disable so people have to log in to their email account and look for the coupon code. As it is now, they see the coupon immediately after entering the e-mail account in the the field.

Is it possible to do that? As I understand it is possible when using pop up box but not when using shortcode?
The problem is that otherwise people can enter random letters like for example xxxx@xxx.xxx toget a coupon!!!
Thank you