Wialon js library createUser issue

Hello everyone, from last week I am stuck in creating user using wialon API. But continuesly I am getting an exception which exhausted me.I want to share code snippet.

Token:
8d5383cf8a10d84eb2b876d1ac6143d20F65AA4C13D7D3C3E7FDB070D058A75FA22009A1

Here is code snippet:

var sess = wialon.core.Session.getInstance(); // get instance of current Session
        var user = wialon.core.Session.getInstance().getCurrUser(); // get current user
         
        wialon.core.Remote.getInstance().remoteCall('core/create_user',{"creatorId":user.getId(),"name":'testing_use',"password":'password',"dataFlags":5});

All screenshot attached.Kindly take a look.It always return error code 6. Gurtam document represent with unknown error.