There are cases when you want to show the countdown right before the beginning of your pre-recorded live stream. In order to do so, take the following steps:
1. Setup a Countdown layer and click on Scenes at the bottom.
2. Click on Plus Icon to add a new Scene with your Pre-recorded video.
3. Make a tick on 'Instant Scenes Switch' and add a Video layer.
4. Launch your stream, by clicking on 'Go Live' button.
5. Once you're ready to switch from a Countdown to your Pre-recorded video, just click on a scene, and it will be synchronized with live right away.