<?

$userName = 'bluebottle';

$curl = curl_init();
$accessToken = '';
$urlShort = 'https://graph.facebook.com/v3.2';

curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);

// получаем pageId
curl_setopt($curl, CURLOPT_URL, "$urlShort/me/accounts?access_token=$accessToken");
$res = json_decode(curl_exec($curl));
$pageId = $res->data[0]->id;

// получаем id бизнес-аккаунта
curl_setopt($curl, CURLOPT_URL, "$urlShort/$pageId?fields=instagram_business_account&access_token=$accessToken");
$res = json_decode(curl_exec($curl));
$instagramBAId = $res->instagram_business_account->id;

// получаем id постов
curl_setopt($curl, CURLOPT_URL, "$urlShort/$instagramBAId?fields=business_discovery.username($userName){media}&access_token=$accessToken");
$res = json_decode(curl_exec($curl));
$allPosts = $res->business_discovery->media->data;

foreach($allPosts as $post){
    var_dump($post->id);
    curl_setopt($curl, CURLOPT_URL, "$urlShort/$post->id?fields=taken_at&access_token=$accessToken");
    $res = json_decode(curl_exec($curl));
    var_dump($res);
    exit();

}

curl_close($curl);