Add controls to Elementor Post Settings panel - Short demonstration to add a custom control to the Elementor Post Settings panel. https://www.damiencarbery.com/2023/11/add-controls-to-elementor-post-settings-panel/

elementor-page-settings.php

<?php
/*
Plugin Name: Add controls to Elementor Post Settings panel
Description: Short demonstration to add a custom control to the Elementor Post Settings panel.
Plugin URI: https://www.damiencarbery.com/2023/11/add-controls-to-elementor-post-settings-panel/
Version: 0.1
Author: Damien Carbery
*/

defined( 'ABSPATH' ) || exit;


class AddLoginRequiredSettingsToElementor {
	// Returns an instance of this class. 
	public static function get_instance() {
		if ( null == self::$instance ) {
			self::$instance = new self;
		} 
		return self::$instance;
	}


	// Initialize the plugin variables.
	public function __construct() {
		$this->init();
	}


	// Set up WordPress specfic actions.
	public function init() {
		add_action( 'elementor/documents/register_controls', array( $this, 'register_login_required_document_controls' ) );
		// 
		add_action( 'wp_head', array( $this, 'retrieve_elementor_login_required_value' ) );
	}


	// Add document controls to Page Settings/Settings tab.
	// @param \Elementor\Core\DocumentTypes\PageBase $document The PageBase document instance.
	function register_login_required_document_controls( $document ) {
		if ( ! $document instanceof \Elementor\Core\DocumentTypes\PageBase || ! $document::get_property( 'has_elements' ) ) {
			return;
		}

		$document->start_controls_section(
			'test_section',
			[
				'label' => esc_html( 'Login required' ),
				'tab' => \Elementor\Controls_Manager::TAB_SETTINGS,
				// Other tabs: TAB_STYLE, TAB_ADVANCED
			]
		);

		$document->add_control(
			'login_required',
			[
				'label' => esc_html( 'Login required' ),
				'description' => esc_html( 'Enable to require that the user must be logged in to see this page.' ),
				'type' => \Elementor\Controls_Manager::SWITCHER,
				// Other control types: CHOOSE, COLOR, DIMENSIONS, HEADING, HOVER_ANIMATION, ICONS, RAW_HTML, SELECT, SLIDER, TEXT. 
			]
		);

		$document->end_controls_section();
	}


	// Retrive the value of the Login Required switcher control and add comment to header.
	function retrieve_elementor_login_required_value() {
		if ( defined( 'ELEMENTOR_VERSION' ) ) {
			$current_doc = Elementor\Plugin::instance()->documents->get( get_the_ID() );
			//error_log( 'Current doc: ' . var_export( $current_doc->get_settings(), true ) );

			if ( $current_doc && 'yes' === $current_doc->get_settings( 'login_required' ) ) {
				echo '<!-- Login required for this page -->';
				//error_log( 'Login required for this page.' );
			}
			else {
				echo '<!-- Login NOT required for this page -->';
				//error_log( 'Login NOT required for this page.' );
			}
		}
	}
}
$AddLoginRequiredSettingsToElementor = new AddLoginRequiredSettingsToElementor();