Did not receive 1st stimulus check and already filed income tax. What is my recourse?

Any missing stimulus payments from rounds one and/or two should be included on your 2020 tax return on line 30 of your form 1040.  Check your copy of your tax return.  If you need to download/print you have that option at sign in to your account. 

Here is a link that will help.  

When completing your 2020 tax return you would have been asked if you received any stimulus payments in rounds one and/or two.  If you answered "no" the missing stimulus payments would have been added to your tax return. 

If you answered "yes" you would then have input the amounts of any stimulus payments you received.  Those amounts would be compared to what you were eligible for and any difference would have been added to your tax return. 

If somehow you did not get all the round one/two stimulus amounts on your return the IRS is reviewing return for stimulus calculations and making corrections.  Wait for your return to be processed (refund deposited).  

Go here for more information on Recovery Rebate Credit corrections.  

If your refund is not correct you can then file an amendment to claim the missing Recovery Rebate Credit.  Select the "Amend" option at sign in to your TurboTax account and follow the prompts to make the correction.  You will need to print, sign and mail your amended returns.