1) Click the + icon in the timeline to add a template.
2) Select Screens from the template list.
3) Select a screen option.
4) Click the image in the screen that is on the stage.
5) Click Mask in the toolbar.
6) Click the Swap function.
7) Select a prop or image from the Asset Library.
8) Use the box around the image to adjust its size, or move the screen to border the asset.
9) Click anywhere else in the video maker to stop editing the mask.