yoursite.com/?ipn-test=1 whilst logged in as admin. * Version: 1.0.0 * Author: WooThemes * Requires at least: 4.1 * Tested up to: 4.3 */ if ( ! defined( 'ABSPATH' ) ) { exit; } add_action( 'wp_loaded', 'paypal_sandbox_ipn_tester' ); function paypal_sandbox_ipn_tester() { if ( ! empty( $_GET['ipn-test'] ) && current_user_can( 'manage_options' ) ) { $response = wp_safe_remote_post( 'https://www.sandbox.paypal.com/cgi-bin/webscr', array( 'body' => array( 'test_ipn' => 1, 'cmd' => '_notify-validate' ) ) ); if ( ! is_wp_error( $response ) ) { wp_die( 'SUCCESS' ); } else { wp_die( 'FAIL - ' . $response->get_error_message() ); } } }