I am a member of AAA and USAA. Where do I apply a promo code for a discount?

When you use an affiliate discount you have to start from the affiliate's web site.   Go to one of those sites to start your return.

https://ttlc.intuit.com/community/charges-and-fees/help/how-do-i-get-my-turbotax-affiliate-partner-discount/00/26509

How to get your Partner Discount

https://ttlc.intuit.com/community/charges-and-fees/help/how-do-i-get-my-turbotax-affiliate-partner-discount/00/26509 

You have to start by logging in at the AAA or USAA website and continue accessing your return though them.