Use the following JS code on your website.
Note: – Replace sliding id cp_id_9fa7a with your style_id.
You may get the style id by going to Design -> Advance Design Options -> Scroll down and copy the style ID

var slideinid = "cp_id_9fa7a";
var slide_in_id = jQuery(".cp-"+slideinid).data("class-id");
var slidein = jQuery("."+slide_in_id);
slidein.addClass('si-open');
jQuery(window).trigger('slideinOpen',[slidein]);