How to handle error from php handler file - php

Question

If there is an error in the js/send_to_telegram.php file, then the error script will work. How to do it?
jQuery("form").submit(function () {
var form_data = jQuery(this).serialize();
jQuery.ajax({
type: "POST",
url: "js/send_to_telegram.php",
data: form_data,
success: function (result) {
donemodal.style.display = "block";
},
error: function (jqXHR, exception) {
errormodal.style.display = "block";
}
});
});
in js/send_to_telegram.php the following code:
$token = "5306003979:AAEPK2NhlxW";
$chat_id = "497358";
$txt = htmlspecialchars($_POST["text"]);
$sendToTelegram = fopen("https://api.telegram.org/bot{$token}/sendMessage?chat_id={$chat_id}&parse_mode=html&text={$txt}","r");
Now, even if you enter the wrong token in $sendToTelegram, it returns success. How to get error if token is wrong?

Answer 1

Short answer: It doesn't use API response status code unless you tell him does that. What if we sent multiple HTTP requests and got different status codes? Which of them should be used?
Solution: This is what you need:
<?php
function post($url, $fields = []) {
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_POST, 1);
if (is_array($fields) && count($fields)) {
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($fields));
}
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$result = curl_exec($ch);
curl_close($ch);
return json_decode($result);
}
$response = post("https://api.telegram.org/bot{$token}/sendMessage", [
'chat_id' => $chat_id,
'text' => $txt,
]);
if ($response->ok) {
echo '{"message": "ok"}';
} else {
http_response_code(500);
echo '{"message": "Something went wrong"}';
}