The Recovery rebate credit on line 30 is for the first 2 Stimulus payments if you didn't get the full amount or you now qualify for more. It either adds to your refund or reduces a tax due.
The first round was 1,200 per person or 2,400 for a couple and 500 for each dependent under 17.
The second round was 600 for each person listed and dependents under 17.
And it is really based on your 2020 return and situation. So if you qualify for more it will be on 1040 line 30. To calculate the amount of your recovery rebate credit, you have to first calculate what your stimulus payment should be based on your 2020 tax return, then subtract what you actually received.
