If you used and paid for the online program then there is no fee to amend it now ...
See this TurboTax FAQ for help with amending:
https://ttlc.intuit.com/questions/1894381-how-to-amend-change-or-correct-a-return-you-already-filed
If you still need assistance then ask from inside the downloaded federal program to get it ...
Please use the following link to contact Customer Support for further assistance.
https://ttlc.intuit.com/community/using-turbotax/help/what-is-the-turbotax-phone-number/00/25632
