Deductions & credits

Good day all.  I'm the OP.  I saw new activity on this thread, so decided to toss out some observations.

DoninGA is correct:  I cannot claim the missing EIP as a credit on my 2020 taxes.  IRS Publication 5486 clarifies that.

I received EIP 3 a month or so ago.  I haven't filed my 2020 taxes yet, so the IRS (apparently) used my 2019 return to decide I'm eligible.  That begs the question of why didn't the IRS use my 2019 return for the second EIP 🤔  I hope Critter-3 is correct about not having to send it back 😲

Hoodat