No sound with 2 phones on facebook

I am new to manycam. I am trying to run 2 inputs from 2 phones. I get great video input from both and the switching works great, however when I go like to facebook, there is only video and no sound from either. I have checked to make sure neither is muted. The add microphone option on the manycam dash does not allow to add the phone as a microphone. Help please.