要路由 Slack 通知到适当的位置，需要在可通知的实体上定义一个 routeNotificationForSlack 方法，这将会返回通知被发送到的 Webhook URL。Webhook URL 可通过在 Slack 组上添加一个 “Incoming Webhook” 服务来生成：

<?php

namespace App;

use Illuminate\Foundation\Auth\User as Authenticatable;
use Illuminate\Notifications\Notifiable;

class User extends Authenticatable
{
    use Notifiable;

    /**
     * Route notifications for the Slack channel.
     *
     * @param  \Illuminate\Notifications\Notification  $notification
     * @return string
     */
    public function routeNotificationForSlack($notification)
    {
        return 'https://hooks.slack.com/services/...';
    }
}