Have you already retrieved and installed your TurboTax product you purchased at Costco? If so, see if you can use the method in this FAQ to move from Online TurboTax to desktop software.
One important point in the FAQ is that if your data from Online also includes a state return, you need to install the state software into your desktop product before doing the switch, or you can get an error message.
FAQ: How do I switch from TurboTax Online to desktop TurboTax?
https://ttlc.intuit.com/turbotax-support/en-us/help-article/intuit-product-orders/switch-turbotax-online-turbotax-cd-download/L8oxEJNu5_US_en_US