Connect amibroker with Pi

I'm trying to connect amibroker with Pi. read the details and came across with below statement


Launch AmiBroker

If everything has happened correctly, as soon as you launch AmiBroker, you should see the Pi Bridge button turn from red to green at the bottom of the Pi screen.


*Even if you don’t see a green light, we have added a small check in the AFL  if(!brd.GetConnectionStatus()) brd.Reconnect();  to reconnect the bridge before the order is fired."

I don't see the green colour in my PI screen. 

Anyone know how to connect?