php 中缺少参数

Missing to param in php

我在我的离子项目中使用 Nexmo 进行 OTP 验证。我制作了以下 php 文件用于发送短信。

请看这个link。我正在使用本教程。 https://ampersandacademy.com/tutorials/ionic-framework-3/automate-sms-otp-verification-using-ionic3-with-nexmo-part1

<?php
require_once 'vendor/autoload.php';

header("Access-Control-Allow-Origin: *");
header('Access-Control-Allow-Credentials: true');
header("Access-Control-Allow-Methods: GET, POST, OPTIONS");
header("Access-Control-Allow-Headers: Content-Type");


$NEXMO_TO = $_GET['mobile'] ?? '';
$NEXMO_FROM='Ampersand OTP';
$MESSAGE='1551 Ampersand OTP';

$client = $client = new Nexmo\Client(new Nexmo\Client\Credentials\Basic('XXXX', 
'XXXXXXXX'));


$message = $client->message()->send([
'to' => $NEXMO_TO,
'from' => $NEXMO_FROM,  
'text' => $MESSAGE
]);

echo "Sent message to " . $message['to'] . ". Balance is now " . 
$message['remaining-balance'] . PHP_EOL;

?>

但是当我点击这个 php 文件时,它给出了以下错误。

Fatal error: Uncaught Nexmo\Client\Exception\Request: Missing to param in C:\xampp\htdocs\nexmosms\vendor\nexmo\client\src\Message\Client.php:75 Stack trace: #0 C:\xampp\htdocs\nexmosms\send-sms.php(20): Nexmo\Message\Client->send(Object(Nexmo\Message\Message)) #1 {main} thrown in C:\xampp\htdocs\nexmosms\vendor\nexmo\client\src\Message\Client.php on line 75

脚本中未设置变量 $_GET['mobile']

使用这个来检查它是否存在:

$NEXMO_TO = (!empty($_GET['mobile'])) ? $_GET['mobile'] : '';

从 PHP 7 开始,您必须使用这样的缩写形式:

$NEXMO_TO = $_GET['mobile'] ?? '';