Before using the External Connection, you must enable the AT interface in the NinjaTrader settings. External connection only works with the default port 36973.
Now add the External Connection to your configured connections.
Click your External connection in the Connections menu.
After that, the External Connection block will turn green.
Open the chart with the desired instrument in NinjaTrader, for example EURUSD. In the data series settings, change “Price based on” to Bid for Forex(CFD) or Last for futures.
Check the ATI box. After a successful connection, you will see a confirmation in the log window and the Ask and Bid prices on the chart. After that, the price chart will be updated synchronously with the MetaTrader chart.