How to change Username in linux system

I have tried to install a professional cvx on a linux machine.
When I have ran the cvx_setup on matlab command window it showed that
License host:
Username: root
Host ID: 842b2b959f09 (ethic)

But as I know I can not fill out the license web page due to the Username since it is root.
How can I change the Username to one that I can request a license?

I appreciate your help in advance.

Try running matlab as root (go to matlab /bin directory and do: sudo ./matlab) ???

I know that CVX’s license requirements prompted this question, but it really is not CVX-related. It’s an operating system issue. Please find a more appropriate forum for your question.