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Before you entered the 1099-K, did you select that this was for Personal Item Sales?  If so, then on the next screen you should enter the 1099-K, then on the following screen, you will see the I sold some times at a loss or had no gain or All items were sold at a loss or had no gain.  

If you do not see that, you can try deleting the 1099-K you entered and then re-enter it making sure you select that these were personal item sales.