notify.py

def send_notification(data, user, req_user, email):
    channel_layer = get_channel_layer()
    group_name = 'user_id_{0}'.format(user.id)
    async_to_sync(channel_layer.group_send)(group_name,
                                            {
                                                "type": "notify",
                                                "text": data,
                                            },
                                            )
    if email:
        send_mail(subject='Уведомление', message=f"{data}", from_email=req_user.email,
                  recipient_list=[user.email])  # from_email-от кого и recepient_list-кому
    notify = Notification.objects.create(sender=req_user, message=data)
    notify.receivers.add(user)
    notify.save()