Trying to add my Marketplace info but it’s not letting me. When I click the option to add nothing happens. Suggestions?

You can add forms as long as you didn't submit your return. If you did, you need to amend it in order to add your 1095-A form.

1. Open your return 
2. Go to Deductions and Credits.
3. Scroll down to Medical
4. Select Affordable Care Act (1095-A)