Try this one:
$ch = curl_init("https://www.cloudflare.com/api_json.html");
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER,false);
// handling of -d curl parameter is here.
$param = array(
'a' => 'cache_lvl',
'tkn' => '8afbe6dea02407989af4dd4c97bb6e25',
'email' => 'sample@example.com',
'z' => 'ex'
);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($param));
$result = curl_exec($ch);
curl_close($ch);
print $result;