had you look this post?
Django-channels sending message when model changes
You can use something like this:
from django.db import models
from django.dispatch import receiver
...
@receiver(models.signals.post_save, sender=Comment)
def send_comment(sender, instance, **kwargs):
async_to_sync(channel_layer.group_send)("chat_name", {"type": "send_comment"})
You can find more signals options at Django signals and more about channel layers outside of consumers at here