Simulate OmniKassa automatic response message with WordPress

omnikassa.php

<?php

define( 'WP_USE_THEMES', false );

require './wp-blog-header.php';

// Post
$url = 'https://www.example.com/';

$data = 'key1=value1|key2=value2|key3=value3';

$secret_key = '002020000000001_KEY1';

$body = array(
	'Data'             => $data,
	'InterfaceVersion' => 'HP_1.0',
	'Seal'             =>  hash( 'sha256', $data . $secret_key ),
);

$result = wp_remote_post( $url, array(
	'user-agent' => 'Java/1.6.0_45',
	'body'       => $body,
) );

var_dump( $result );

echo '<textarea rows="50" cols="100">', esc_textarea( wp_remote_retrieve_body( $result ) ), '</textarea>';