An error occurred while making a request to the panel, if the issue persists please create an issue on github.
201 POST https://panel.example.com/api/application/users

            adminInterface.getAdminAPI().getUsersController().createNew()
                    .setEmail(customerId.toString()   "@example.com")
                    .setUsername(customerId.toString())
                    .setPassword(customerId.toString())
                    .setFirstName("Han")
                    .setLastName("Solo")
                    .setLanguage("en")
                    .execute();