what's wrong with 2023? if it is just the fact it was not yet filed, then you'll need to print it out and mail it per Turbotax instructions. It can no longer b e-filed. be sure to attach W-2/withholding forms. Also it would be wise to mail it using a tracking method.
if it is not finished, you'll need to purchase a desktop version and follow the above instructions. Since 2023 hasn't been filed use zero in 2024 for prior year agi when e-filing.
I suggest you complete 2023, if needed, before doing 2024. if you finish 2023 using a desktop version some data from 2023 will not transfer to 2024 so be careful.
https://turbotax.intuit.com/personal-taxes/past-years-products/