Simple auto-publishing plugin, no backend, just set as you like :-) - Used i.e for https://lipercubo.it

auto-publish-wordpress.php

<?PHP 
/*
Plugin Name: Manual Autopublisher (no backend)
Plugin URI: https://capolooper.it
Description: Quickly and easily auto republish random old posts
Version: 0.1
Author: Salvatore
Author URI: https://capolooper.it
License: GPL2
*/

add_action ('wp', 'cronstarter_activation');
function cronstarter_activation() {
	if( !wp_next_scheduled( 'mycronjob_republish_posts' ) ) {  
	   wp_schedule_event( time(), 'twicedaily', 'mycronjob_republish_posts' );  
	}
} 
add_action ('mycronjob_republish_posts', 'republish_old_post_2022'); 

function republish_old_post_2022( ){
	$ids = get_posts(array(
			'fields'          => 'ids', // Only get post IDs
			'posts_per_page'  => -1,
			// 'category'        => '1675,7' // optional: republish from specifical category
		        // other options from get_posts
		));

		shuffle($ids);

		$postdate = date( 'Y-m-d H:i:s' ); //data di oggi
		$my_post = array(
			'ID'            => $ids[0], 
			'post_date' 	=> $postdate
		);
	
		wp_update_post( $my_post ); 
}

// unschedule event upon plugin deactivation
function cronstarter_deactivate() {	

	// find out when the last event was scheduled
	$timestamp = wp_next_scheduled ('mycronjob_republish_posts');
	
	// unschedule previous event if any
	wp_unschedule_event ($timestamp, 'mycronjob_republish_posts');
} 
register_deactivation_hook (__FILE__, 'cronstarter_deactivate');