I need to amend my federal and state tax returns from 2019 as they were rejected by the federal due to IND 031 04 how do I access them and refile through turbo tax.

You do NOT amend a return that was never accepted or processed.   You need to fix the reason for the rejection which is for the prior year AGI and it is not needed for a mailed in return  ...  so just  print, ink sign and mail in the prior year return.  

To access your current or prior year 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) or Download .tax file

What should I do if my submitted return is not shown at the bottom of my turbotax account so I can correct the rejection problem?

Make sure you are using the exact same User ID and password you used to prepare the tax return. It's very easy to inadvertently create a duplicate account.  To double-check how many TurboTax accounts you have, please see How many Intuit Accounts do I have with TurboTax?
For assistance with fixing a rejected return, see here

@mkarlisch.