rentalist.php

<?php
/*
Plugin Name: Rentalist
Description: Create a plugin with sub menu and script.js jquery included with ajax admin
 */


if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

// plugin definitions
define( 'RENTALIST_URL', plugin_dir_url( __FILE__ ) );

class Rentalist {

	function __construct() {
		$this->rentalist_setting = 'rentalist_settings';
		$this->rentalist_sync    = 'rentalist_sync';
		add_action( 'admin_menu', array( $this, 'rentalist_add_menu' ) );
		add_action( 'admin_enqueue_scripts', array( $this, 'rentalist_enqueue_scripts' ) );
	}

	function rentalist_add_menu(): void {
		$rentalist_main_page_slug = $this->rentalist_sync;
		add_menu_page( "Rentalist", "Rentalist", "manage_options", $rentalist_main_page_slug, array(
			$this,
			'rentalist_sync'
		), 'dashicons-smiley', 7 );
		add_submenu_page( $rentalist_main_page_slug, "Sync / Import", "Sync / Import", "manage_options", $this->rentalist_sync, array( $this, "rentalist_sync"), 7 );
		add_submenu_page( $rentalist_main_page_slug, "Setting", "Setting", "manage_options", $this->rentalist_setting, array($this,"rentalist_setting"), 7 );
	}

	function rentalist_enqueue_scripts() {
		if ( isset( $_REQUEST['page'] ) && in_array( $_REQUEST['page'], [$this->rentalist_setting,$this->rentalist_sync] ) ) {
			wp_enqueue_script( 'rentalist_admin_js', RENTALIST_URL . 'js/rentalist.js', 'jQuery', 1, true );
			wp_localize_script( 'rentalist_admin_js', 'rentalist_ajax_object', array( 'ajax_url' => admin_url( 'admin-ajax.php' ) ) );
		}
	}

	function rentalist_sync() {
		echo "<div class='wrap'>rentalist_sync</div>";
	}

	function rentalist_setting() {
		echo "<div class='wrap'>rentalist_setting</div>";
	}
}

$rentalist = new Rentalist();