Yes there’s a form where it asks you to enter amounts for the 2020 check and the 2021 January check since it was authorized in 2020. If you received it you put in the amount you received. If it ends up being a credit, they might not have given you all the money you are eligible for at first, like for dependents.
I had a daughter in 2020 and so understandably she wasn’t on my 2019 taxes so I’m having to claim the other part of the money owed based on that.
