cURL error 7

[Mostafa-shenawy]

This is my code to convert html to PDF, but I get cURL error 7

$ilovepdf = new Ilovepdf('{public_key}','{secret_key}');

$myTaskHtmlpdf = $ilovepdf->newTask('htmlpdf');

$file = $myTaskHtmlpdf->addUrl($post_url);

$myTaskHtmlpdf->execute();

$myTaskHtmlpdf->download();

This is the error details

PHP Fatal error: Uncaught GuzzleHttp\Exception\ConnectException: cURL error 7: (see https://curl.haxx.se/libcurl/c/libcurl-errors.html) for https://api32.ilovepdf.com/v1/upload in /vendor/guzzlehttp/guzzle/src/Handler/CurlFactory.php:210