Sending Slack notifications with monolog

example.php

<?php

require_once 'vendor/autoload.php';

$logger = new \Monolog\Logger('GeneralLogger');
$slackHandler = new \Monolog\Handler\SlackHandler('slack-token', '#channel', 'username');

$logger->pushHandler($slackHandler);
$slackHandler->setLevel(\Monolog\Logger::ERROR);

$logger->error("Just an ERROR message. It works!");