我配置pusher, Laravel Broadcasting,Laravel Echo向我的用戶發送通知。它適用于單個私人頻道。我有兩個私人頻道。App.User{id}YouthAdd.YouthAdd{id}App.User{id}但是通知僅通過Channel傳遞我怎樣才能從其他渠道發送通知呢？我的用戶類namespace App;use Illuminate\Broadcasting\PrivateChannel;use Illuminate\Foundation\Auth\User as Authenticatable;use Illuminate\Notifications\Notifiable;class User extends Authenticatable{    use Notifiable;    /**     * The channels the user receives notification broadcasts on.     *     * @return string     */    public function receivesBroadcastNotificationsOn()    {        return 'App.User.'.$this->id;        return 'YouthAdd.YouthAdd.'.$this->id;    }}我的 Channels.php 路由文件Broadcast::channel('App.User.{id}', function ($user, $id) {    return (int) $user->id === (int) $id;});Broadcast::channel('YouthAdd.YouthAdd.{id}', function ($user, $id) {    return (int) $user->id === (int) $id;});我的前端<script>  var userId = $('meta[name="userId"]').attr('content');    Echo.private('App.User.' + userId)    .notification((notification) => {        toastr.warning(notification.title, notification.name, {closeButton: true, timeOut: 5000000});    });      Echo.private('YouthAdd.YouthAdd.' + userId)      .notification((notification) => {          console.log(notification.youth);          toastr.error(notification.youth.name, notification.youth.nic, {closeButton: true, timeOut: 5000000});      });    </script>任何人都可以回答這個問題嗎？