How to designate image in Featured Image Slider

Hi, I am customizing Chicago Pro for our website. This is an incredible full-featured theme but sooo easy to use. Thanks for your work on it! I want to use the Featured Image Slider, but it does not seem to be working. I can use Featured Page Slider and Featured Post Slider, but no field appears to designate which image I want to display. Can you help? I'd prefer not to have to create a new page just to display an image in the slider.