why webSocket connection failed?

Question

I've been trying to cerate a chat app using Django with webSocket,in console I got this, error WebSocket connection to 'ws://127.0.0.1:8000/ws/chat/room/' failed: room/:20 I'm not using Redis for implementing Django channels, İt is just a simple chat app runs on local server host

views.py

def room(request, room_name):
    return render(request, "chatroom.html", {"room_name": room_name})

routing.py

websocket_urlpatterns = [
    re_path(r"ws/chat/(?P<room_name>\w+)/$", consumers.ChatRoomConsumer.as_asgi()),
]

consumer.py

class ChatRoomConsumer(AsyncWebsocketConsumer):
    async def connect(self):
        self.room_name = self.scope["url_route"]["kwarges"]["room_name"]
        self.room_group_name = "chat_%s" % self.room_name
        await self.channel_layer.group_add(self.room_group_name, self.channel_name)
        await self.accept()
        # to know which group we should send to
        await self.channel_layer.group_send(
            self.room_group_name,
            {
                "type": "tester_message",
                "tester": "hello world",
            },
        )

    async def tester_message(self, event):
        tester = event["tester"]
        await self.send(text_data=json.dumps({"tester": tester}))

    async def disconnect(self, close_code):
        await self.channel_layer.group_discard(self.room_group_name, self.channel_name)

chatroom.html

 <div id="user-hello">
     
    </div>
    <!-- convert an object into a JSON object -->
    {{room_name|json_script:"room-name"}}
    <script>
          // convert a JSON object in text format to js object that can be used
        const roomName=JSON.parse(document.getElementById('room-name').textContent);
      //create websocket connection script
        const chatSocket=new WebSocket(
          'ws://' +
            window.location.host +
            '/ws/chat/' +
            roomName +
            '/'
           
        );
        
        //receive a massege 
         chatSocket.onmessage=function(e){
            const data=JSON.parse(e.data)
            console.log(data);
            document.querySelector('#user-hello').innerHTML=(data.tester)
        }
    </script>
 

settings.py

INSTALLED_APPS = [
    "channels",
    "django.contrib.admin",
    "django.contrib.auth",
    "django.contrib.contenttypes",
    "django.contrib.sessions",
    "django.contrib.messages",
    "django.contrib.staticfiles",
    "chat",
]

DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"
ASGI_APPLICATION = "core.routing.application"
CHANNEL_LAYERS = {
    "default": {
        "BACKEND": "channels.layers.InMemoryChannelLayer",
    }
}