NOTE: This feature is not enabled by default. If you need access to this feature, please contact your SPM, your Vidpresso contact or firstname.lastname@example.org.
In Vidpresso you'll notice the "RTMP Sources" tab on the right side.
This tab has the necessary info for your encoder.
Copy the RTMP Stream URL (RTMP Address) and Stream Key by clicking on them in Vidpresso and paste them into your encoder. When done, start streaming from your encoder.
When you're ready you can click the "Add to current stream as source" button.
Your RTMP source will then show up at the bottom of your screen, next to any other cameras you may have added. It can be switched, placed in a PiP or split screen just like any source.