If you are using Wowza's ClearCaster device to encode your Facebook Live streams, you can directly connect your Vidpresso graphics to that encoder.
Inside of Vidpresso, on the Stream Setup tab you need to set the "Origin" dropdown to "Wowza" This will generate a link you need to use in your ClearCaster interface.
Simply copy and paste this link into your ClearCaster interface.
Inside of your ClearCaster account, go to your broadcasts page and select an existing Scheduled live post, or create a broadcast.
Setup your broadcast as desired. Look for the Section labeled "Titling and Graphics" and change the dropdown to show "Vidpresso."
Paste the Link you copied from Vidpresso into this box.
Inside of Vidpresso you'll notice that the Start button has been greyed out and your'e instructed to Start the stream from your ClearCaster interface.