The Lomography X Zenit Petzval Art Lens is a fully manual lens, and this is the reason why your camera is not detecting it.
In order to shoot with the Petzval, we advise you to follow these steps:
1. Set your camera to manual mode.
2. Insert the appropriate aperture plate into the plate slot given your shooting conditions.
3. Set the F-stop on the body to match the aperture plate currently inserted into your lens.
4. Adjust the exposure time so the internal light meter shows the correct exposition.
5. Adjust the focus with the lens knob, aim your camera at your subject and press shutter release button.