public function edd_activate() {

        $license_key = trim($_POST['key']);

        $ch = curl_init();
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);
        curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/x-www-form-urlencoded'));
        curl_setopt($ch, CURLOPT_TIMEOUT, 0);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_URL, 'https://wpfusionplugin.com/?edd_action=activate_license&license=' . $license_key . '&item_name=' . urlencode( 'WP Fusion' ) . '&url=' . home_url());
        curl_setopt($ch, CURLOPT_SSLVERSION, 1);
        $response = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);

        if ($errno = curl_errno($ch)){
            $error_message = curl_strerror($errno);
            wp_send_json_error( $error_message );
            die();
        }

        // decode the license data
        $license_data = json_decode( $response );

        // $license_data->license will be either "valid" or "invalid"

        // Store the options locally
        $this->set('license_status', $license_data->license );
        $this->set('license_key', $license_key );

        if($license_data->license == 'valid') {
            wp_send_json_success('activated');
        } else {
            wp_send_json_error( '<pre>' . print_r($license_data, true) . '</pre>' );
        }

        die();
    }