Responsive Wallpapers and Flex Skin ad products can only be purchased via a direct buy with the Publisher for the site the ad product will be served on. These ad products are not available via a programmatic buy.
Responsive Wallpapers and Flex Skins require specialized 3rd Party tags to display on the publisher's site, which are provided by the Flexitive team. These tags are tailored to fit the dimensions and layout of the site the wallpaper is hosted on.
If you would like any assistance with setting up a flex skin or responsive wallpaper, reach out to us at firstname.lastname@example.org.