Your question has me confused... 2020 paroll taxes can be deferred and paid later (half in 2021 and half in 2022). You have the option of making this deferment when filing your 2020 return. So if you "paid" deferred payroll tax in 2021 it would presumably be for the 2020 tax year that you had chosen to defer. If you chose not to defer, I don't know if you can amend your return and make this election now. Even if you can, I'm not sure how you would benefit since the first payment due date has already come and gone.
