Надим

<?php

header('Content-Type: application/json; charset=UTF-8');

ini_set('error_reporting', E_ALL);
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);

$authKey = '********************';
$oauthClientId = '****************';
$requestURL = 'https://api.partner.market.yandex.ru/v2/campaigns/21614343/hidden-offers.json';

$data = array(
	'hiddenOffers' => array(
		array(
			'offerId' => 146688,
			'comment' => 'clear markret',
			'ttlInHours' => 720
		)
	),
);

$data_string = json_encode($data);

$result = file_get_contents($requestURL, null, stream_context_create(array(
			'http' => array(
				'method' => 'POST',
				'header' => array(
					"Authorization: OAuth oauth_token=$authKey, oauth_client_id=$oauthClientId\r\n" .
					"Content-Type: application/json; charset=utf-8\r\n" .
					"Content-Length: " . strlen($data_string) . "\r\n" .
					"Host: " . parse_url($requestURL)['host']
				),
				'content' => $data_string
			)
		)
	)
);

echo $result;