Lens distortion and Glare with Transparent Background

Levi writes:

Check out this video if you want to add glare and/or lens distortion to your renders. I wanted to make a render of my model with transparent background and lens distortion, but when I applied the lens distortion on it the transparent background became black, and I didn’t know what could I do. Finally I figured out how I can remove the blackness and I wanted to share with you guys.