If this is your first-time filing, you will have to print & mail your return.
If you are using TurboTax Online, select File > Filing Hub* from the left side menu. Then click on "Print & Mail your return(s)" to go to a page where you can download a special version of your return to print off and mail.
*If you don’t see the Filing Hub option under File, then select CRA Online Mail and continue forward from there to get to the Filing Hub.