> Quote - I orig export my renders to a png file and when I saved it to jpg to post it here, background automatically turned white.

If the "background automatically turned white", the original render PNG must have had a transparent background. So go back to my suggestion for fixing the problem. Did you try it?

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)