It sounds to me like you need to file a 2019 and 2020 to get your stimulus money. My suggestion would be to file your 2019, 2020, and 2021 at the same time.
Filing your 2019 and 2020 will probably get you the 1st and 2nd stimulus payments.
Filing your 2021 tax return will get you the 3rd stimulus payment. Filing your 2021 will also get you the Advanced Child Tax Credit/Refundable Child Tax Credit which depending on the age of your child could be either $3,000 or $3,600. If your child is under the age of 6 then the credit is $3,600, if 6 and older then $3,000.
