You can stream to Facebook via RTMP by getting RTMP credentials from Facebook's Create Live page and inputting them into your Mevo.
Go to https://www.facebook.com/live/create in a browser, then click Create Live Stream.
On the right side, choose where you want your stream to go (e.g. Your Timeline, a Group), your audience, and any title or caption you'd like to go with it.
In the middle of your screen, you will see your Server URL and Stream Key.
Configure any optional settings, then input the Server URL and Stream Key into a new RTMP destination in the Mevo app.
Tap Go Live in the upper right corner of the Mevo app.
You will see a preview of your stream in Facebook, at which point you can then click Go Live in the bottom right corner of the Create Live page to post the live video to Facebook.