Facebook Messenger бот, используя пример Postback?

Это то, что вы имеете в виду?

https://github.com/pimax/fb-messenger-php-example/blob/master/index.php

$data = json_decode(file_get_contents("php://input"), true, 512, JSON_BIGINT_AS_STRING);

if (!empty($data['entry'][0]['messaging'])) {

foreach ($data['entry'][0]['messaging'] as $message) {

$command = "";

// When bot receive message from user
if (!empty($message['message'])) {
$command = $message['message']['text'];
}
// When bot receive button click from user
else if (!empty($message['postback'])) {
$command = $message['postback']['payload'];
}
}
}// Handle command
switch ($command) {
// When bot receive "text"case 'text':
$bot->send(new Message($message['sender']['id'], 'This is a simple text message.'));
break;
// When bot receive "image"case 'image':
$bot->send(new ImageMessage($message['sender']['id'], 'https://developers.facebook.com/images/devsite/fb4d_logo-2x.png'));
break;
// When bot receive "image"case 'local image':
$bot->send(new ImageMessage($message['sender']['id'], dirname(__FILE__).'/fb4d_logo-2x.png'));
break;
// When bot receive "profile"case 'profile':
$user = $bot->userProfile($message['sender']['id']);
$bot->send(new StructuredMessage($message['sender']['id'],
StructuredMessage::TYPE_GENERIC,
[
'elements' => [
new MessageElement($user->getFirstName()." ".$user->getLastName(), " ", $user->getPicture())
]
]
));
break;
// When bot receive "button"case 'button':
$bot->send(new StructuredMessage($message['sender']['id'],
StructuredMessage::TYPE_BUTTON,
[
'text' => 'Choose category',
'buttons' => [
new MessageButton(MessageButton::TYPE_POSTBACK, 'First button'),
new MessageButton(MessageButton::TYPE_POSTBACK, 'Second button'),
new MessageButton(MessageButton::TYPE_POSTBACK, 'Third button')
]
]
));
break;
// When bot receive "generic"case 'generic':
$bot->send(new StructuredMessage($message['sender']['id'],
StructuredMessage::TYPE_GENERIC,
[
'elements' => [
new MessageElement("First item", "Item description", "", [
new MessageButton(MessageButton::TYPE_POSTBACK, 'First button'),
new MessageButton(MessageButton::TYPE_WEB, 'Web link', 'http://facebook.com')
]),
new MessageElement("Second item", "Item description", "", [
new MessageButton(MessageButton::TYPE_POSTBACK, 'First button'),
new MessageButton(MessageButton::TYPE_POSTBACK, 'Second button')
]),
new MessageElement("Third item", "Item description", "", [
new MessageButton(MessageButton::TYPE_POSTBACK, 'First button'),
new MessageButton(MessageButton::TYPE_POSTBACK, 'Second button')
])
]
]
));

break;
// When bot receive "receipt"case 'receipt':
$bot->send(new StructuredMessage($message['sender']['id'],
StructuredMessage::TYPE_RECEIPT,
[
'recipient_name' => 'Fox Brown',
'order_number' => rand(10000, 99999),
'currency' => 'USD',
'payment_method' => 'VISA',
'order_url' => 'http://facebook.com',
'timestamp' => time(),
'elements' => [
new MessageReceiptElement("First item", "Item description", "", 1, 300, "USD"),
new MessageReceiptElement("Second item", "Item description", "", 2, 200, "USD"),
new MessageReceiptElement("Third item", "Item description", "", 3, 1800, "USD"),
],
'address' => new Address([
'country' => 'US',
'state' => 'CA',
'postal_code' => 94025,
'city' => 'Menlo Park',
'street_1' => '1 Hacker Way',
'street_2' => ''
]),
'summary' => new Summary([
'subtotal' => 2300,
'shipping_cost' => 150,
'total_tax' => 50,
'total_cost' => 2500,
]),
'adjustments' => [
new Adjustment([
'name' => 'New Customer Discount',
'amount' => 20
]),
new Adjustment([
'name' => '$10 Off Coupon',
'amount' => 10
])
]
]
));
break;
case 'set menu':
$bot->setPersistentMenu([
new MessageButton(MessageButton::TYPE_WEB, "First link", "http://yandex.ru"),
new MessageButton(MessageButton::TYPE_WEB, "Second link", "http://google.ru")
]);
break;
case 'delete menu':
$bot->deletePersistentMenu();
break;
// Other message received
default:
$bot->send(new Message($message['sender']['id'], 'Sorry. I don’t understand you.'));
}