Using the “vitual path” (= ‘crt.crt’) is not possible to find the crt.crt.
However.
I’m using this:
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_TIMEOUT, '10');
curl_setopt($ch, CURLOPT_USERAGENT, 'MyPHP/1.0')...