How can i use transparent renderer with outlinepass

i read and try in the example
but no use
here is my code
webgl_postprocessing_outline.html (30.6 KB)
this is the background image

i add the code of outlinepass then there is nothing

Welcome to the forum @ShootToThrill

It will be easier for people to help you if you share your current progress in a live format. You can use this template as a starting point