Can I still receive help with turbo tax since my refund was rejected

The 2019 AGI is on your 2019 federal tax return, Form 1040 Line 8b

To access your prior year online tax returns sign onto the TurboTax website with the User ID you used to create the account - https://myturbotax.intuit.com/

Scroll down to the bottom of the screen and on the section Your tax returns & documents click on Show.  Click on the Year and Click on Download/print return (PDF)

If you used the desktop CD/Download editions installed on your computer, the only copy of your tax data file and any PDF's will be on the computer where the return was created.  TurboTax does not store online any returns completed using the desktop editions.

Or go to this IRS website for free federal tax return transcripts - https://www.irs.gov/individuals/get-transcript

For a fee of $43 you can get a complete federal tax return from the IRS by completing Form 4506 - http://www.irs.gov/pub/irs-pdf/f4506.pdf

If the 2019 AGI you are entering is correct there is a good possibility that the IRS does not have the AGI for your Social Security number in their database.  Try entering a 0 (zero) for the 2019 AGI and e-file the 2020 federal tax return again.