You cannot change your username yourself. Write an email to [email protected] from the email address stored in your account, tell us what your current username is and what you would like to change it to.
Please let us know if you have wishes or have encountered bugs. We give our best to make Runalyze as good as possible for you. - Therefore we would be interested in your suggestions for improvement. In general most questions, problems and ideas are more appropriate to ask in the forum.