Ok ... when you set up direct debit payments and/or request a payment plan with direct debit payments not only does this information show up on the screen where you have to agree to it before you can continue but on the filing instruction pages in the PDF. So if you did not read the fine print at that time the same information is on the filing instruction pages that print with the return. Save a PDF to see the instructions.
Now if the IRS is not showing your payments you made then review the receipt from the online payments ... did you accidentally say they were for 2018 or 2020 instead of 2019?
And if you have proof of the payments made simply send copies of the proof back with the bill to contest the balance due and penalties/interest. Follow the notice instructions carefully.
