In TurboTax (TT), enter at:
Federal Taxes Tab (Personal for H&B version)
Deductions & Credits
-Scroll down to:
--Education
--ESA and 529 Qualified Tuition Programs (1099-Q)
If they 529 plan beneficiary did not attend school, you indicate that in that section and no further entries are needed.
If the beneficiary did attend school, you'll need to also enter education expenses too.
In TurboTax (TT), enter at:
Federal Taxes Tab (Personal for H&B version)
Deductions & Credits
-Scroll down to:
--Education
--Education Expenses
TT will calculate the taxable portion and penalty.