Fatal Error in Elementor Pro Class extends

Hello,

I need to extend Elementor Pro “Add To Cart Class” to add style control to it. But when I extend it throws an error: Fatal error: Class ‘Elementor\Widget_Button’ not found.

class FinerFriday_ADD_TO_CART extends ElementorPro\Modules\Woocommerce\Widgets\Add_To_Cart  {
...
}