Online collaboration is better when you can hear and see the other person - just like you are in the same room.
Step 1: Click on the Person icon on the lower right.
Step 2: Board Admin or Team Members select Start Call. Everyone else on the board select Join Call
Step 3: Allow Microphone and Camera
Select the microphone icon to mute or unmute yourself before or you enter a call or during the call
Select Leave call to exit the Video Conference call.