I’m a Canadian citizen living overseas and considered a non-resident of Canada. I receive OAS and QPP pensions. How do I file my taxes?

You can use TurboTax. When it asks you what province you are in, you can choose "Non-Resident". As a non-resident you will need to print and mail your return. 

Also please note that TurboTax only accepts Canadian and US credit cards as payment, unless you use the mobile app. Then you can pay with Apple Pay or Google Pay (depending on your OS).