How to configure local issuer certificate in Wamp using OpenSSL in Laravel project?

Am trying to send SMS Locally with Nexmo but i configured my Wamp server to use OpenSSL but when i try sending, i get this error.

cURL error 60: SSL certificate problem: unable to get local issuer certificate (see http://curl.haxx.se/libcurl/c/libcurl-errors.html)

Am sending the message in a route from my web.php like this,

Route::get( '/sms/send/{to}', function(\ Nexmo\Client $nexmo, $to){
     $message = $nexmo->message()->send([
        'to' => $to,
        'from' => env('NEXMO_NUMBER'),
        'text' => 'Sending SMS from Laravel. Woohoo!'
    ]);
    Log::info('sent message: ' . $message['message-id']);
});

Need help of how i can fix this.

via Chebli Mohamed