If you are getting a refund, there is no penalty for missing the April 15 fling deadline. If you owe tax due, it is late and you are subject to a late filing penalty and interest owed on the amount of tax due as shown on the Form 1040. If you owe penalties or interest, the IRS will send you a bill later after they receive your tax return and the payment for the amount shown on the tax form.
And....as for not being able to find your AGI
Where do I find my AGI?
https://ttlc.intuit.com/community/agi/help/how-do-i-find-last-year-s-agi/01/25947
Your 2022 tax return shows your 2022 Adjusted Gross Income (AGI) If you filed a joint return then the AGI is the same for each of you.
Form 1040 line 11
If you are using the same TT account that you used last year, you should also be able to find this number in your Tax Home for 2023
If entering the amount from your 2022 tax return does not work, then try entering “0” instead. If that does not work and you still cannot e-file, then print, sign, and mail your tax return.
You can get a free transcript of your past return from the IRS:
https://www.irs.gov/individuals/get-transcript
Note: If you filed late or amended your return, your correct 2022 AGI may not be in the system.
https://ttlc.intuit.com/questions/1944348-how-do-i-print-and-mail-my-return-in-turbotax-online
Note: If you mail your federal return, you will also need to mail your state return. You will not be able to e-file your state return.