The error Call to undefined function Symfony\Component\HttpClient\Response\curl_multi_exec() typically occurs when you try to use a function or feature in your Symfony application that depends on the cURL PHP extension, but that extension is either not enabled or not available on your server.
The function curl_multi_exec() is part of the cURL PHP extension, which is used to perform concurrent or parallel HTTP requests. Symfony uses this function when the cURL extension is enabled, but if it is not, you will encounter this type of error.
Possible solutions: Enable the cURL extension in PHP
To check if cURL is enabled, you can run the following PHP code:
<?php
if (function_exists('curl_version')) {
echo "cURL is enabled";
} else {
echo "cURL is not enabled";
}
?>