The Backchannel provides a space where the facilitator can talk to the players privately without anyone else in the team seeing the conversation.
To view messages in the Backchannel, navigate to the 'Menu' tab in the ExCon dashboard, and select Backchannel. There you will be able to see what each player has sent to you and you'll be able to use an open text box to reply to them individually.
The video below shows how the facilitator can access the Backchannel to talk to players individually. The facilitator screen is shown alongside the player screen to demonstrate how the player sees the facilitator actions.