When images are exported, they have a black background. To investigate, I [posted to StackOverflow](https://stackoverflow.com/questions/66197628/how-to-create-a-transparent-background-using-headless-chrome) & [Chromium bugs](https://bugs.chromium.org/p/chromium/issues/detail?id=1178996), and am awaiting feedback.
When images are exported, they have a black background. To investigate, I posted to StackOverflow & Chromium bugs, and am awaiting feedback.