Follow the instructions in the IRS letter for how to respond if you disagree with the amount owed. Read the entire letter carefully and be sure to respond by the deadline in the letter. Do not include an amended return (Form 1040-X) or revised tax return unless the letter says you should.
The main point you have to make in your response is that all of the payments from PayPal were for personal items sold at a loss, so there is no taxable income and no additional tax is due. (You do not have to pay tax on personal items sold at a loss, but you cannot deduct the loss. It's just zero net income.)
What you were supposed to do was report the 1099-K on your tax return, with an offsetting entry to eliminate the income. If you didn't include it in your original tax return, you should have filed an amended return when you got the 1099-K. What the IRS sees now is $26,467.61 of income that was never reported.
Make sure you are clear about what year you are dealing with. You mentioned "2022 taxes" and "my 2022 filing," but you also said "I filled my taxes back in 2022." The tax return that you filed in 2022 would have been for 2021. You filed your 2022 tax return in 2023.
