To autosync your voice-over to the entire video, on the storyboard (which is the screen below):
1. Go to Audio > My uploads > Either drag/drop or select your file to upload > Apply to the entire video.
2. After applying the voiceover, make sure to select Yes, it does if you have an intro/ outro recorded with your voiceover or No, it does not if you do not have an intro/ outro recorded with your voiceover.
3. In a few seconds, AI will autosync the voiceover with your video. If you wish to further adjust the voiceover sync > Click on Adjust Voice-Over.
3. Select the scene to wish to adjust, use the green border lines to adjust the voiceover for the scene. Use the Preview icon to listen to the adjusted voice-over, hit Save and Close once done.
*The 'Autosync a Voice-Over to Entire Video' is not available in the Tier 1 or Starter plan.