My 2019 tax is filled out but not yet submitted. I need to amend it in order to add form 8962. I'm using my android phone. How do I amend?

The TurboTax program calculates, fills in, and files Form 8962 for you, but you must enter the 1095-A and answer the interview questions. 

If you are having a difficult time with the app, open your account online.

I completed the federal and state free turbo tax edition. I did not see anywhere to add form 8962. 

Is this form only available on paid editions of Turbo tax? Where to I reconcile my premium tax credit/payments for the health marketplace?  

Yes, form 8962 for premium tax credits is available with TurboTax online with TurboTax Online Deluxe and higher product. Go to TurboTax product comparison, scroll down, click under one of the TurboTax products "learn more" prompts, the scroll down and click tax forms to see what forms are available in each TurboTax product.