Elementor\Widget_Shortcode::_register_controls PHP Method

    protected function _register_controls()
    {
        $this->start_controls_section('section_shortcode', ['label' => __('Shortcode', 'elementor')]);
        $this->add_control('shortcode', ['label' => __('Insert your shortcode here', 'elementor'), 'type' => Controls_Manager::TEXTAREA, 'placeholder' => '[gallery id="123" size="medium"]', 'default' => '']);
        $this->end_controls_section();
    }