You are reporting an IRS form 1099-B and personal item sales and reporting that all of the items were sold at a loss or had no gain.
Consider removing the IRS form 1099-B and re-entering as Other at the screen Which type of income is your 1099-K for?
At the screen Let's get the info from your 1099-K, select This amount in box 1a is too high or includes some personal transactions. Enter the amount in box 1a.
The amount is reported at the top of Schedule 1.
Retain your records with your income tax files should a tax authority have a question at a later time.
@Ivan L