You would see the discount applied under the file tab when you're finishing the process. However, a lot of people are having trouble applying the discount. To make sure its applied, you would need to clear and start over your return, and go to the 3rd party website applying the discount, and start filing through their page.
Luckily in your case, being a Premier member, you can call our customer service line and speak to a TurboTax agent to go about applying your discount for you.
To get in contact with a phone agent, you would need to sign in to your return, and click contact in the upper right-hand corner.