How to change the background image in builderpress - Please Help

I have worked on builder press for over a month and I cannot find how to change the background behind the title pages. By background If I make a background of the pages it is behind the picture and if I change it to parallex it is in front of the picture? I have no idea where the picture is ( I think it might be pulling it from another website) or where to change it?
It is not in visual composer
it is not in "customisation"
I cannot find it in the editor.
Please help - anyone!

Contact the theme author

Thanks ki-themes