UPDATE: Thank you to anyone who attempted to help... I've concluded that I'm not going to get an answer to this question here, and will need to keep trying to get through to someone at the IRS for confirmation that my 2020 Tax Filing is indeed complete in their system (as it shows online), and they did apply my payments to the 2020 tax I owe (as shown in their system online), and get more clarification for what they are asking for on the green form they mailed me, or if that was a misunderstanding/mistake.
