You will need to enter a 0 (zero) for the 2023 AGI when e-filing the 2024 tax return.
To complete and file a 2023 tax return using TurboTax you would need to purchase, download and install on a personal computer one of the 2023 desktop editions from this website - https://turbotax.intuit.com/personal-taxes/past-years-products/
A 2023 tax return can only be printed and mailed, it cannot be e-filed using TurboTax.
TurboTax only has the current year available on TurboTax Online.
To file a 2023 return, you would need one of the desktop download or CD products. See here for more information about available product versions for tax year 2023.
If you will be receiving a refund for 2023, the IRS will pay you interest on the refund. If you owe additional taxes for 2023, interest and a penalty for late filing may be assessed. See this IRS webpage for more information including how to request that the penalty be waived for reasonable cause.
Be careful with putting in $0, as sometimes your AGI is already updated.
Unfortunately, the IRS doesn't bother sending you notifications or confirmations on what it actually is so you have to check yourself (which is a pain for young people who are doing taxes for the first time, like myself). If they do, it's not intuitive how to set those notifications.
TurboTax prompts you sometimes (as it did for me) to put $0 and I was rejected twice. Also, they're phone and email notifications don't come in at the same time, causing even more confusion on if you're returns were accepted or not. Just a reminder that I won't be using their services again, and I recommend anyone to do the same. Highly recommend FreeTaxUSA
If you didn't file for 2023, entering $0 for your last year's AGI in the Efile interview is the correct way. You will need to choose a 5-digit PIN also.
If you're using TurboTax Online, clear your Cache and Cookies, go back to the File section and step through the interview and enter $0, and try Efiling again.
What was your Reject Error message?