None, if you used an online app for 2023 and will use it again in 2024. the only file that normally exists/needed when you use the online app is the one on the Turbotax servers. Make sure to log into the same account you used for 2023. The file will not be in the new account.
If you are going to use a Windows desktop app for 2024, then you need either the XXXX.tax2023 file in your Turbotax account uploaded to your computer or if you used a Windows desktop app for 2023, then the file in the c:\users\user name\documents\Turbotax folder. there should be two files for 2023. ~xxxxx.tax2023 is a backup file and xxxxx.tax2023 that is the file you need.
