As the host of a broadcast, if you plan to connect with the other participants before and during a broadcast, you'll want to "join your guests in the green room" so they can see and hear you.
When a Guest joins the Green Room (Guest Experience), there will be a popup window that prompts you to join them. From here, you can select which camera and microphone you want to use when connecting with them.
If you miss that popup, you can still join them in the Green Room. To do that, hover over the local camera you'll be using during the live broadcast to participate in the conversation.
Choose "Join guests in green room"
You'll see a Green Message in the upper left corner to indicate that that you're in the green room and your guests can see and hear you.
Verify that your guests can see and hear you. Use the built-in chat window or unmute them in the Live Sources panel to talk.
Here's what your guest will see when they join the broadcast (note: this is from the mobile app view):