I am newer to working with lottie. I created an animation where documents come on the screen from outside the composition at the bottom. When I create the lottie file, it shows items below the bottom line when I don’t want it to export anything other than what is in the composition in after effects. (The top image shows the animation in after effects and the bottom is a preview of the lottie json file).
@phillip256 I would create a mask for each object to “block” them from being seen until they’re above the “line”
Play with Alpha Channel, or Inverted Alpha Channel