You can only use TurboTax to NETFILE forms that have been filled out using TurboTax. If you download and fill out a form from the Canada Revenue Agency (CRA) you would need to print it out and mail it in.
You can find the address where you need to send it on the last page of the t1135.
Winnipeg Taxation Centre
Data Assessment & Evaluation Programs
Validation & Verification Section
Foreign Reporting Returns
66 Stapon Road
Winnipeg MB R3C 3M2