@ lou34880
asked: "Where do I enter prior to your product key?"
What does that mean? Can you please rephrase that and provide some details so we can understand your question? What are you trying to do? Are you using desktop software (you mentioned a product key) or are you in Online TurboTax (which doesn't use a product key?) The product key (license code) is used during the software installation. Are you trying to prepare a 2024 return in 2024 software or a prior-year return in a prior-year software?
Be aware this is a public user community forum, so don't post any personal info in this public forum.
Do you mean prior year product key? Did you buy a prior year Desktop program? Or have a 16 digit License Code? If the program download is not listed in your Online account you may have to call in. What did you buy and where? What year?
To enter a License Code you first have to download the program on a full Windows or Mac computer. Then install it. During the installation it will ask for the code.