Depends ... if you didn't have ACA marketplace insurance it is in the Business tab down under  Less Common Business Situations ...see screenshot ...

If you did have ACA insurance and have a 1095-A to enter then you do that in the Personal tab ... click on health insurance and follow the screen instructions.

Well they changed the program from last year ... if you have a Sch C then it is listed in the Common expenses under Insurance of all things...  😉