WebSocket Connection Failed.

I'm trying to connect websocket api.
The frontend is Next.js and it's on Azure static web app
And the backend is Django, it's on Azure app service.
I enabled CORS in the backend, so frontend in localhost has no problem when I connect websocket api of backend (it's on Azure App Service.).
I can't find any reason or message on the browser console why connection is failed.

```
WebSocket connection to 'wss://assessmate.azurewebsites.net/ws/notify/' failed:
```
```
_app-456513e57728c64c.js:149 WebSocket error:
Event {isTrusted: true, type: 'error', target: WebSocket, currentTarget: WebSocket, eventPhase: 2, …}
isTrusted: true
bubbles: false
cancelBubble: false
cancelable: false
composed: false
currentTarget: WebSocket {url: 'wss://assessmate.azurewebsites.net/ws/notify/?toke…
I6MX0.zgUVAmgIStnz7iIj8OXyIhPIK4QqvFbyvPNsjhal86A', readyState: 3, bufferedAmount: 0, onopen: ƒ, onerror: ƒ, …}
defaultPrevented: false
eventPhase: 0
returnValue: true
srcElement: WebSocket {url: 'wss://assessmate.azurewebsites.net/ws/notify/?toke…
I6MX0.zgUVAmgIStnz7iIj8OXyIhPIK4QqvFbyvPNsjhal86A', readyState: 3, bufferedAmount: 0, onopen: ƒ, onerror: ƒ, …}
target: WebSocket {url: 'wss://assessmate.azurewebsites.net/ws/notify/?toke…I6MX0.zgUVAmgIStnz7iIj8OXyIhPIK4QqvFbyvPNsjhal86A',
readyState: 3, bufferedAmount: 0, onopen: ƒ, onerror: ƒ, …}
timeStamp: 11759.199999999255
type: "error"
[[Prototype]]: Event
```
Please help us!