amending your 2019 return has nothing to do with the stimulus. it is confusing.
the basis of your credit is the info on your 2020 tax return. Plain and Simple.
if your child met the criteria for the first 2 stimulus payments (he was under 17 as of 12.31.20), then it'll appear on Line 30.
there is no form to write for. it the credit didn't appear on Line 30, he wasn't eligible.
ps the third stimulus is a different story. if he was a dependent on your 2020 tax return, you'll get the credit.
