If you qualify the offer should appear at the lower right of your start screen after logging in to Fidelity. Clicking on that will take you to the TurboTax site and you should see that the download is free for TurboTax Premier. I forget if you have to click downloaded product first.
If your AGI is low enough, you can file for free through an IRS program. My AGI was low enough last year that I could use TaxAct (which is the program I like anyway) for free.
They close for a bit around the end of the year but open up again in late January: