that is correct, but note closely which tax returns go with which stimulus
the way the IRS works is if you are owed a refund you have three years from the tax deadline to submit the tax return, so for 2020, the tax deadline is May 17, 2021, so the three years expires on May 17, 2024. after that date you will not get the refund.
if you owe money, there is no deadline, you always owe it.
if you are due a refund, why wouldn't you submit it now?
