Hey @allenov,
Welcome to the Community!
In this case, I would recommend registering your log-in credentials with your email address as a username. You can do this by clicking on ``Register Now`` in the pop-up window after clicking on ``Sign In`` from the website.
You then want to click on the option that shows you're the ``Account Holder``. You'll need your account number and postal code.
This will then send you a link that will help you finalize the registration.
Once you're logged in, you can click on ``Billing & Payments`` and view your invoice details.
I hope this helped clarify things a little. 
