Orca server :: how do i get result as svg

Hi. This is my first post, so apologies if the wrong group.

I have installed plotly orca and I can run it as a server and POST json data to it. This returns an image/png. I wish to return svg but I cannot find any way of doing this. Is there a request parameter or part of the json data that I can tell it to return svg? can I configure the server somehow?