In this tutorial you will see the bulkgate bulk sms sender using this your can send bulk SMS in USA its allows you to send message with link it needs two things when you create account to send message first is application id, token  you can place at the multiple_number.php you can add those things to work with bulkgate.

require_once './vendor/autoload.php';
$connection = new BulkGate\Message\Connection('', ''); //application id, token
$sender = new BulkGate\Sms\Sender($connection);

if (isset($_POST['numbers'])) {
    $numbers = $_POST['numbers'];
    $message = $_POST['message'];
    foreach (explode("+", $numbers) as $phone) {

        $response = new BulkGate\Sms\Message($phone, $message);
        if ($sender->send($response)) {
            $data = array(
                "response" => "success",
                "current" => '+' . $phone

            echo json_encode($data);
} else {
    echo "Please add your number list and message!";

its an example complete sender in the zip file you can dowload and put inside your server and replace the application id and token to work with bulkage api.

How to controll the sending speed?

go to this location C:\xampp\htdocs\telnyx\assets\mail.js in this file when you scroll down you will see there is settimeout function to controll the sedning limit 1000ms means 1 secound you can control you sending milit.

if you have any questions and doubts you can write the comment below the post.