Remote Post Check for WooCommerce

plugin.php

<?php
/*
Plugin Name: Remote Post Check for WooCommerce
Description: Checks the remote post and displays the result in the WordPress admin page with troubleshooting info.
Version: 1.0
Author: Stefan Pejcic
Author URL: https://pejcic.rs
*/

function check_remote_post() {
    $enable_remote_post = true;

    if ( $enable_remote_post ) {
        $post_response_code = get_transient( 'woocommerce_test_remote_post' );

        if ( false === $post_response_code || is_wp_error( $post_response_code ) ) {
            $response = wp_safe_remote_post(
                'https://www.paypal.com/cgi-bin/webscr',
                array(
                    'timeout'     => 10,
                    'user-agent'  => 'WooCommerce/' . WC()->version . '; ' . get_bloginfo( 'url' ),
                    'httpversion' => '1.1',
                    'body'        => array(
                        'cmd' => '_notify-validate',
                    ),
                )
            );
            if ( ! is_wp_error( $response ) ) {
                $post_response_code = $response['response']['code'];
            }
            set_transient( 'woocommerce_test_remote_post', $post_response_code, HOUR_IN_SECONDS );
        }

        $post_response_successful = ! is_wp_error( $post_response_code ) && $post_response_code >= 200 && $post_response_code < 300;

        // Display the result in WordPress admin page with troubleshooting info
        add_action( 'admin_notices', function () use ( $post_response_successful, $post_response_code, $response ) {
            $message = $post_response_successful ? 'Remote post successful (HTTP ' . $post_response_code . ')' : 'Remote post failed';

            if ( ! $post_response_successful ) {
                $error_message = is_wp_error( $response ) ? 'Error: ' . $response->get_error_message() : 'HTTP ' . $post_response_code;
                $message .= '<br><strong>Troubleshooting Info:</strong> ' . esc_html( $error_message );
            }

            echo '<div class="notice notice-info is-dismissible"><p>' . wp_kses( $message, 'post' ) . '</p></div>';
        } );
    }
}

// Run the function on admin_init hook
add_action( 'admin_init', 'check_remote_post' );