Sorry, Online is only for 2024 now. Online for 2023 and prior is closed now so you can not start a new 2023 or prior return or finish one. You have to do each year separately
How to prepare a prior year return
https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-prepare-a-prior-year-tax-return/00/25...
To do a prior year return you have to buy the Desktop program here,
https://turbotax.intuit.com/personal-taxes/past-years-products
You will need a full Windows or Mac to install it on.
If you have a simple return and want to file for free you can fill out the forms by hand. Here are some basic forms…..
Here is the IRS 2023 Form 1040
https://www.irs.gov/pub/irs-prior/f1040--2023.pdf
or if you want bigger type use 1040SR for Seniors,
https://www.irs.gov/pub/irs-prior/f1040s--2023.pdf
And 2023 Instructions
https://www.irs.gov/pub/irs-prior/i1040gi--2023.pdf
2023 Tax and EIC Tables
https://www.irs.gov/pub/irs-prior/i1040tt--2023.pdf
Sch 1 : https://www.irs.gov/pub/irs-prior/f1040s1--2023.pdf
Sch 2 : https://www.irs.gov/pub/irs-prior/f1040s2--2023.pdf
Sch 3 : https://www.irs.gov/pub/irs-prior/f1040s3--2023.pdf
Then when you do file 2024 enter 0 for the 2023 AGI since you are filing 2023 late.
You have to print and mail prior year returns. When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s. Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS received the return. Don’t forget state.
Important! Mail Federal and State in separate envelopes and mail each year in separate envelopes.
