Form 7206

TurboTax will add the form when you enter your self-employment health insurance premiums.   To enter those premiums in the desktop software, go to your Business Schedule C - Other Common Business Expenses.   Then select Insurance Payments; you can enter your long-term care premiums on the next screen.   

The deduction will show up on Line 17 of Schedule 1.   You will also find Form 7206 in your forms list under your Schedule C. 

How do I amend my federal tax return for this year?  (choose desktop at the bottom)

My screen doesn't look like the one you posted. The only topic I have is "Less common business expenses", not "Other common business expenses". Looks like I can go directly to Schedule C and enter there. Is that correct?

Yes, from the Topic List, you can select Less common business situations to get to the entry screen.   It doesn't get entered on Schedule C, so use the Less common business situations, then select Self-employed Health insurance paid.