You go in the Online Billing Settings page, which you can find in the My Account page (but I just provided a direct link for you).
Edit: ninja'd by FidoMegan! 
Hey Alejandra!
Welcome to the community!
You can register for Online Billing directly on fido.ca in your My Account. Here's how:
- Go to fido.ca and log-in to your My Account section.
- Under "Payment Information" select "Register for Online Billing"
To complete the registration, you need to:
- Provide an email address.
- Read and accept the Terms and Conditions.
An email will be sent to the and you must click the link from the email or copy/paste the link in your internet browser.
- Provide your Fido number and postal code
- Click Continue.
The View Online billing hyperlink option will be available once you log out and back in.
Hope this helps!
