I have changed the domain for you since you verified it is your account, there may be a few minutes before this is reflected in your account portal and in cPanel.
Also remember that there may be a small delay before the domain is working fully, this is called propagation time (meaning the time it takes for Internet to learn about the new domain. Usually it works within the hour, but it can take considerably longer.
Don't forget to update any scripts you may have installed to reflect the change as well to ensure they work correctly.