We are not big fans of sliders and generally don't recommend them. Please read this article for more information: https://yoast.com/opinion-on-sliders/
Nevertheless, our plugin provides a shortcode to display a slider with reviews: [cusrev_reviews_slider]. Please see Review Extensions tab in the plugin's settings for full information about the arguments supported by this shortcode.
To use any shortcode provided by our plugin, you must enable Reviews Shortcodes checkbox on Review Extensions tab of the plugin's settings.