In TurboTax, a negative number is virtually always entered with a minus sign before it, not parentheses.
Regardless, I suspect, due to the nature of the form, that the section presented will have to be completed in Forms Mode, which is only supported in the desktop (installed on a computer) versions of TurboTax.
The lines on the K-1 in that section will most likely have to be entered and calculated manually.
