Client code - DELL6358

I am using nodejs package for the same here is the code

app.get("/", (req, res) => {
  let smart_api = new SmartAPI({
    api_key: 'api_key'
  });
  console.log(smart_api)
  // If user does not have valid access token and refresh token then use generateSession method
   smart_api
    .generateSession('client_code', 'password', 'totp')
    .then((data) => {
      return  smart_api.getProfile();
    })
    .then((data) => {
      console.log(data)

    })
    .catch((ex) => {
      console.log(ex)    });


  res.json({ message: "Welcome to bezkoder application." });
});

Trying to login but getting this error
{
success: false,
message: 'Invalid Token',
errorCode: 'AG8001',
data: ''
}