Lighting a video in real time online

How to light a video in real time online  ?

1. Upload    a video as a background
2.  Upload a spotlight image    with a transparent background and a small opacity ratio for the light
3. Make sure to choose a picture size smaller than the canvas size to overlay the video
4. Start to record  your video
5. Move the spotlight image over the video
6. To add a visual effect, move the image outside then inside the canvas
7. Pause  your video
8. Download your video    with a lighting visual effect