octicon-link" viewBox="0 0 16 16" version="1.1" width="16" height="16" aria-hidden="true">Laravel Facebook Messenger Provider

'providers' => [
    ...
    Casperlaitw\LaravelFbMessenger\LaravelFbMessengerServiceProvider::class,
    ...
],

'alias => [
    ...
    'Menu' => Casperlaitw\LaravelFbMessenger\Facades\MessengerMenu::class,
    ...
],

 return [
     'verify_token' => env('MESSENGER_VERIFY_TOKEN'),
     'app_token' => env('MESSENGER_APP_TOKEN'),
     'auto_typing' => true,
     'handlers' => [App\DefaultHandler::class],
     'custom_url' => '/chatbot', // like this
     'postbacks' => [],
 ];

<?php

namespace App;

use Casperlaitw\LaravelFbMessenger\Contracts\BaseHandler;
use Casperlaitw\LaravelFbMessenger\Messages\ReceiveMessage;
use Casperlaitw\LaravelFbMessenger\Messages\Text;

class DefaultHandler extends BaseHandler
{
    /**
     *  handle method is required. 
     */
    public function handle(ReceiveMessage $message)
    {
        $this->send(new Text($message->getSender(), "Default Handler: {$message->getMessage()}"));
    }
}

<?php

namespace App;

use Casperlaitw\LaravelFbMessenger\Contracts\PostbackHandler;
use Casperlaitw\LaravelFbMessenger\Messages\ReceiveMessage;
use Casperlaitw\LaravelFbMessenger\Messages\Text;

class StartupPostback extends PostbackHandler
{
    // If webhook get the $payload is `USER_DEFINED_PAYLOAD` will run this postback handler
    protected $payload = 'USER_DEFINED_PAYLOAD'; // You also can use regex!

    /**
     * Handle the chatbot message
     *
     * @param ReceiveMessage $message
     *
     * @return mixed
     */
    public function handle(ReceiveMessage $message)
    {
        $this->send(new Text($message->getSender(), "I got your payload"));
    }
}

return [
    'verify_token' => env('MESSENGER_VERIFY_TOKEN'),
    'app_token' => env('MESSENGER_APP_TOKEN'),
    'auto_typing' => true,
    'handlers' => [App\YourHandler::class],
    'postbacks' => [
        App\StartupPostback::class,
    ],
];