You only enter if you got a 1095A for ACA or Marketplace insurance. You don't enter 1095B or a 1095C or Medicare. So when you get to the health insurance question just say No.
To enter insurance
Federal Taxes (Personal using Home and Business)
Deductions and Credits
Scroll down to Medical
On Affordable Care Act (Form 1095-A), click the start or update button
Say No.