How to output a video file (logo) from After Effects with a transparent background?

Question

Adobe After Effects

The project has several layers with text and shapes with superimposed shadow effects. There is no background as such.
Tried to set following values ​​in Output Module Settings:
Format: QuickTime; Channels: RGB+Alpha; Video Codec: Animation/PNG
After the output, I get a video with a black background. You can use such a logo using the Screen overlay method, but in addition to the black background, black shadows are also excluded.

Answer 1

I did everything as described by you, there are no problems in AE, the alpha channel is present. Maybe it's in the settings of the video editor that you use after After Effects. If this is Vegas, then you can try the following: Right Click on the fragment -> Properties, in the window that appears, on the Media tab, opposite the Alpha Channel property, select Premultiplied.