I just configured the device.
I enabled mqtt server config wit username and password.
Unfortunately in mqtt logs I cannot see the username from the smart-mac but just:
1557525454: New connection from 10.x.xx.xxx on port 1883.
1557525454: Sending CONNACK to 10x.xx.xxx (0, 5)
1557525454: Socket error on client , disconnecting.
Customer support service by UserEcho