Wordpress set post thumbnail with media_sideload_image function

set-image.php

<?php

require_once(ABSPATH . 'wp-admin/includes/media.php');
require_once(ABSPATH . 'wp-admin/includes/file.php');
require_once(ABSPATH . 'wp-admin/includes/image.php');

$url    = 'http://wordpress.org/about/images/logos/wordpress-logo-stacked-rgb.png';
$title  = "Anything you want";
$postId = 1;

function setPostAttachment($attId)
{
    $att    = get_post($attId);
    $postId = $att->post_parent;
    
    set_post_thumbnail($postId, $attId); // set as post thumbnail
    
    update_field('image', $att->ID, $postId); // update acf field
}

add_action('add_attachment', 'setPostAttachment');
media_sideload_image($url, $postId, $title);
remove_action('add_attachment', 'setPostAttachment');