PHP使用curl发送HTTP请求时，如何使用本地的SSL证书

public static function add_clientcert_header( $ch ) {
        $certDir = Connector::getKymaBasepath();
        $keyFile = $certDir . '/privkey.pem';
        $certFile = $certDir . '/certs/crt.pem';

        curl_setopt($ch, CURLOPT_SSLKEY, $keyFile);
        curl_setopt($ch, CURLOPT_SSLCERT, $certFile);
        curl_setopt($ch, CURLOPT_VERBOSE, true);
        
        return $ch;
    }