As ColleenD3 explained, you must visit the HSA section of TurboTax and enter as a personal contribution the amount that Fidelity deposited on your behalf. TurboTax prepares Form 8889 from the information that you provide here and from the entry you make in box 12 of TurboTax's W-2 form. There is no way in online TurboTax to make entries directly on Form 8889, nor should you want to since doing so would void TurboTax's accuracy guarantee with respect to the calculations on that form.
Federal -> Deductions & Credits -> Medical -> HSA, MSA Contributions
