1. Go to this page and download the library: Download jeremykenedy/slack-laravel library. Choose the download type require.
2. Extract the ZIP file and open the index.php.
3. Add this code to the index.php.
<?php
require_once('vendor/autoload.php');
/* Start to develop here. Best regards https://php-download.com/ */
Slack::assertMessageSent(function($messages) {
// search in all messages
});
Slack::assertMessageSentTo($channel, function($messages) {
// search in all messages posted to $channel
});