如何从localhost连接到web主机mysql db

I have a problem to connect to my webhost MYSQL from my localhost.

I have a host (www.printcity24.com) with mysql db and I use this code to connect to mysql db :

<?php
    $db_path = mysqli_connect('printcity24.com', 'myuser', 'mypass', 'mydb', '3306');
    if(!$db_path) {
        echo mysqli_connect_error();
    }else{
        echo "Connected successfully";
    }

?>

when i call this code from printcity24.com every thing is OK and connect to mysql db successfully.

but i created a localhost by xampp on my computer and when i call this code i got this error :

Warning: mysqli_connect(): MySQL server has gone away in C:\Program Files\XAMPP\htdocs\index.php on line 2

Warning: mysqli_connect(): (HY000/2006): MySQL server has gone away in C:\Program Files\XAMPP\htdocs\index.php on line 2 MySQL server has gone away

I talk to my web host admin and opened 3306 port on my host and added % to Manage Access Hosts on CPanel > remote MYSQL

but i still have problem to connection.