Retirement tax questions

You were suppose to include the one you got in 2021.   The payment you got in January or February 2021 is an Advance and based on your 2020 return.  So you tried to get it again.  The year you got it doesn't matter.  The Stimulus entry screen even says the second one is between Dec 2020 and Jan 2021 so you should include any payments you received in January and February.