add_action('elementor/element/post/document_settings/after_section_start', 'function_to_test', 20 , 2 );

function_to_test(\Elementor\Core\DocumentTypes\Post $page){
$page->start_controls_section(
			'content_section',
			[
				'label' => __( 'Content', 'plugin-name' ),
				'tab' => \Elementor\Controls_Manager::TAB_CONTENT,
			]
		);

		$page->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' ),
			]
		);

		$page->end_controls_section();
}