360 video with Transparent Background that is less than 4MB and MP4

I am pretty new to After Effects and I am trying to work on a VR project. I have created animations with transparent backgrounds and when I add them to the Render Queue I read on a different forum answer to change it to RGB + Alpha, and change Quicktime to Quicktime PNG. When I try to save it as Quicktime PNG I dont have all the options shown in the photo in the other post and I definitely do not have the PNG. I am using this video with ar.js so I need it to be less than 4MB, and MP4. What do I do? Thanks!