You can create an account by clicking on the top-right icon. You'll be taken to the log in page - then click below the login form on the Create Account button to create your account.
Note: if the below applies:
If you'd like to update your payment method or change your address, log in to your account and click 'Manage Subscriptions' and go to 'Billing' Information'. Here you will be able to view and amend your account details.
Choosing a selection results in a full page refresh.