$this->add_control(
            'widget_title',
            [
                'label' => __( 'Title', 'plugin-domain' ),
                'type' => \Elementor\Controls_Manager::TEXT,
                'default' => __( 'Default title', 'plugin-domain' ),
                'placeholder' => __( 'Type your title here', 'plugin-domain' ),
            ]
        );