Include Subtitle in modal window

I use a plugin to display product info inside a modal window. The dev for that plugin originally set it up to display product subtitles using the following:

 if($this->wcqv_display['show_product_title']==='1'){

        	add_action( 'wcqv_product_data', 'woocommerce_template_single_title');
			add_action( 'wcqv_product_data', function(){
				$cl = new wc_ps_subtitle;
				$cl->the_subtitle();
			});

        }

Since the update a couple of months ago this no longer works. Are you able to advice how I can update the above to restore subtitles to the modal window, please?

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