Hello, I forgot to specify that I have NOT received $600 stimulus check in 2020, but already e-filed my Tax Return, and it was accepted. How can I amend it ?

When it comes to the stimulus check questionnaire section of the program, if you made a mistake in your entries (or entry), and already e-filed, the IRS has asked that you NOT file an amended return as they will make the correction on their end based on the information that they have in their system. Therefore, if they do have you in their system as having "received" the second stimulus payment (meaning, that they have that they produced one and sent it out - whether to a bank or via USPS), then you will not receive that money. IF, however, they have in their system that one was not generated for you when it should have been, they will make the correction on their end. I am more inclined, however, to advise you to wait until your 2020 return is fully processed and you've received your refund - review it - and if it does not include the $600 you are still waiting for, then amend the return to correct the previous error.