There is not a special link for the free filing for military. You only need to start your tax return by entering personal information. You will be asked if you are active military and you indicate Yes.
When entering your income you Must have a military W-2 to enter. After entering your W-2 there will be a screen asking about Uncommon Situations check the box for Active Military.
If you are enlisted personnel then you can use any of the TurboTax online editions at no charge. Except for the Live edition, those are not free for military.