That is a great question, and thank you for asking before you registered your account. It's a lot easier to help you with this if you have not finished filing.
First I strongly recommend
clearing your browsers cookies and history. Otherwise it my auto direct
you away from the specific link you need to apply the discount.
Once you have done that follow these steps.
To
get your partner discount, make sure to prepare your taxes at the
special TurboTax site provided by your bank, credit union, or insurance
company – not at TurboTax.com, which charges the non-affiliate price.
Go to the special website provided by your bank, credit union, or insurance company and click the TurboTax link or icon.
This will take you to the special TurboTax-branded affiliate site with the discounted pricing.
Select your product, sign in, and start on your tax return.
When
you get to the Review your order screen (in the File section) you'll
see the discounted price along with the message Your discount has been
applied.