@Bonnied1 If you purchased the TurboTax desktop edition from Costco then you should have received a 16 character license code. The license code is used during the installation of the desktop software. The license code is not used with the online editions.
Follow the instructions in the TurboTax support FAQ for installing the desktop software with the license code - https://ttlc.intuit.com/turbotax-support/en-us/help-article/license-information/install-turbotax-cd-...
