Adjusted gross income for 2018 does not match.

Your 2018 Adjusted Gross Income is on line 7 of your 2018 form 1040. If you used TurboTax online to prepare and file your return, you can access it using this link: https://ttlc.intuit.com/community/prior-year-return/help/how-do-i-access-my-prior-year-return/00/27010

If you have entered your correct AGI and your return was rejected for that reason, the IRS may not have your correct AGI in their database. You can try entering the number 0 instead of your AGI. That will often work. 

When did you file 2018? If it was late in the year try putting in zero for the AGI. And see, https://ttlc.intuit.com/community/rejections/help/what-if-i-entered-the-correct-agi-and-i-m-still-getting-an-e-file-reject/00/27031

If your spouse died during 2019 there is a problem efiling and you will have to mail your return

How to correct the AGI
https://ttlc.intuit.com/community/agi/help/where-do-i-correct-my-agi-in-turbotax-online/00/26311

If you can’t get it to efile you will have to print and mail it.
How to mail a return from the Online version
https://ttlc.intuit.com/community/printing/help/how-do-i-print-and-mail-my-return-in-turbotax-online/00/26258

Be sure to attach copies of your W2s and any 1099s that have withholding on them.  You have to mail federal and state in separate envelopes because they go to different places.  Get a tracking number from the post office when you mail them for proof of filing.


For AGI Reject code 031
https://ttlc.intuit.com/community/rejections/help/e-file-reject-ind-031-04-or-ind-032-04-the-agi-or-self-select-pin-from-last-year-doesn-t-match-irs/00/27197