Simple Telegram Bot but it doesn't respond to commands (PHP) - php

Question

I'm fairly new to all of this, but I have created a simple telegram bot to test their functionality. I have set the webhook and I'm using ngrok for the "host". However when I type a command the bot just doesn't do anything.
Does anyone know how to fix this?
Here is the index.php file:
<?php
require('token.php');
require('config.php');
try{
$ngrokUrl = "ngrok url";
$bot = new TelegramBot($token);
$jH = new jsonHandler($token);
var_dump($bot->setWebhook($ngrokUrl));
$webhookJson = $jH->getWebhookJson();
$chatId = $jH->getChatId($webhookJson);
$msg = $jH->getText($webhookJson) !== "" ? $jH->getText($webhookJson) : "";
switch($msg){
default:{
if ($msg[0] == '/')
$bot->sendMessage($chatId, 'The command does not exist');
break;
}
case '/test':{
$msg = 'test test';
$bot->sendMessage($chatId, $msg);
break;
}
case '/help':{
$msg = 'Help!';
$bot->sendMessage($chatId, $msg);
break;
}
}
}catch(ErrorException $e){
echo $e->getMessage();
}
?>
And the config.php file:
<?php
function fetchApi($url){
$req = curl_init($url);
$resp = curl_exec($req);
if($resp == false){
$error = curl_error($req);
curl_close($req);
throw new ErrorException($error);
}
else{
curl_close($req);
//return $resp;
}
}
class TelegramBot{
protected $tUrl;
function __construct($token){
$this->tUrl = "https://api.telegram.org/bot".$token;
}
function setUrl($method){
return $this->tUrl."/".$method;
}
function sendMessage($chatId, $msg){
$data = [
'chat_id' => $chatId,
'&text' => $msg
];
$url = $this->setUrl("sendMessage?".http_build_query($data));
fetchApi($url);
file_get_contents($url);
}
class jsonHandler extends TelegramBot{
function getWebhookJson(){
$json = file_get_contents("php://input");
return json_decode($json, true);
}
function getChatId($jsonDecoded){
return $jsonDecoded["message"]["chat"]["id"];
}
function getText($jsonDecoded){
return $jsonDecoded["message"]["text"];
}
}
?>