How or where do I file an 8863 aotc in TurboTax?

TurboTax automatically does that for you, if you qualify for a tuition credit.

In TurboTax (TT), enter at:

Federal Taxes Tab (Personal for H&B version)

Deductions & Credits

“I’ll choose what I want to work on” button

-Scroll down to:

--Education

  --Education Expenses and Scholarships (1098-T)

There's a new urban myth among college students that says they can get a $1000 from the government just for filing a tax form. For most of them, they simply aren't eligible. A full time unmarried student, under age 24, even if you don't qualify as a dependent, is only eligible for the refundable portion of the American Opportunity Credit if he supports himself by working. You cannot be supporting yourself on parental support, 529 plans or student loans & grants. It is usually best if the parent claims that credit. 

You cannot claim a credit if you are, or can be, claimed as a dependent by someone else.

Reference: Line 7 instructions for form 8863. https://www.irs.gov/instructions/i8863