The direct answer to your question is that ISO Health Insurance meets the official standards of coverage set forth by the US government, as can be confirmed by viewing the following Frequently Asked Questions (FAQ) webpage:
https://www.isoa.org/FAQ
Thus, in TurboTax, you would indicate that you had "acceptable" or "valid" health insurance all year, through a private policy (but not one purchased through an Affordable Care Act / Obamacare marketplace exchange, which is something different).
That said, the longer answer to your question involves determining whether TurboTax is actually the "right" tax preparation product for you in the first instance, given your status as an international student. For a detailed discussion on that subject, and before you file your US tax return using TurboTax, it is respectfully recommended that you read the following AnswerXchange post, and apply that information to your own circumstances:
https://ttlc.intuit.com/questions/3652295
Thank you for asking this question.