I am sorry, but if you do not have your 5 digit e-filing pin from last year, then you will need to use the last year's AGI to e-file your return.
It is not saved in the TurboTax system. It is your personal e-filing pin that you used last year.
From the IRS site:
Special Instructions to Validate Your 2020 Electronic Tax Return
If your 2019 tax return has not yet been processed, enter $0 (zero dollars) for your prior year adjusted gross income (AGI).
If you used the Non-Filers: Enter Payment Info Here tool in 2020 to register for an Economic Impact Payment in 2020, enter $1 as your prior year AGI. For more information, see Claiming the Recovery Rebate Credit if you aren’t required to file a tax return.
For additional information refer to the following link:
Validating Your Electronically Filed Tax Return
