$curl = curl_init('https://api.inokufu.com/learningobject/v2/lang');
//Download the certificate from 'https://api.inokufu.com/' to avoid SSL errors and replace 'certInokufu.cer' with the name of your downloaded file
curl_setopt($curl,CURLOPT_CAINFO,__DIR__ . DIRECTORY_SEPARATOR . 'certInokufu.cer');
$data = curl_exec($curl);
var_dump(curl_error($curl));