@ dr-2000-2006-sh
If you did not file a return for 2023, then you can use an AGI of 0 for efiling purposes. It should ask you for your 2023 AGI, where you can enter 0. If you don't see a place to enter 2023 AGI of 0 (it may be on a subsequent screen), if it asks if you filed a return last year, choose that you did not file a 2023 return, then TurboTax should enter a 2023 AGI of 0 for you in the background, and you should be able to efile.
While you can prepare tax year returns out of order like that, be aware that if you have anything that carries over from 2022 to 2023, or from 2023 to 2024, such as capital loss carryovers, etc., you might have to amend the 2024 return down the road.
