Deductions & credits

If the 1099-k is simply reporting proceeds, much like a garage sale, from selling personal items but not trying to make a profit (and not selling any items at a gain)

Enter the 1099-k under

Income

Other Common Income

Income from Form 1099-K

Start 

"Did you get a 1099-K?" YES

SELECT PERSONAL ITEM SALES on the "Choose which type of income your 1099-K is for" screen

Continue

Enter the information from the 1099-K

Continue

Select "ALL ITEMS WERE SOLD AT A LOSS OR HAD NO GAIN" on the "Personal Item Sales" screen

Continue and Done

That's all you need to do, there is no income and no loss (personal item sales cannot generate a loss)