First, I used the demo site that came with eCart 4 (which is the same as eCart 3, I think).
In the cart.php page, I added the Display Manager with the default values.
In that page (since it has a checkout button) I used the Checkout Wizard.
On the first screen, I chose the first option (Accept credit cards and Paypal). On the second screen, I selected the left one (Paypal Website Payments Standard). Entered my ID, unchecked "I will provide shipping", checked "No thanks, I'll handle tax calculation myself" (since I won't charge tax). The order option on next screen wasn't available (since I unchecked the shipping checkbox earlier). I chose the Crisp design. On last screen, I used the default value and I checked the "Use PayPal sandbox server for testing" and clicked Finish.
So, it created my pages, but the confirm.php page had a USD currency_code instead of CAD.
For the eCart object, I had selected French as language and $ CAD as currency symbol.