Auto login as WordPress Admin

autologin.php

<?php

include('wp-load.php');

$user_id = 1; // Assuming admin user id is 1
wp_set_current_user($user_id);
wp_set_auth_cookie($user_id);

if ( is_user_logged_in() ) {
	header('Location: '.admin_url());
}
else {
	echo 'Failed';
}