Im trying to fix my 2019-2020 rejected tax return that needed my 2018 AGI, I got an email saying I can come back and fix it but i see no option to do so, how do i fix it?

Last year I was trying to file my taxes but it said I needed to enter in my 2018 AGI, Ive never filed taxes before on my own so I didnt have my w2 from that year, I very recently just got ahold of my 2018 W2, and I received an email from TurboTax themselves saying I can come back and resubmit my 2019 tax return, but i dont see any way to do that, is there any way i can do that without paying for the software? I cannot afford to pay for that right now.