PHP curl error: SSL certificate problem: unable to get local issuer certificate settlement program

        //Avoiding ssl authentication for https
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
        curl_setopt($ch, CURLOPT_SSLVERSION, false);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);

Just add the last two sentences.

Read More: