Making my Image Transparent

Hello - I am trying to make the attached image transparent. I would like to be able to just export the connected dots as one trasnparent image. When I am exporting, I am clicking the box that says "make transparent" but it's not saving as a tranparent .png. Any suggestons? For whatever reason, I am unable to attach the illustrator file, but I have attached the non-transparent .png that I downloaded from Adobe Stock