Problem in y-websocket connection

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Describe the bug
I'm unable to code Syncing in Codemirror.
I'm getting a problem y-websocket connection
"y-websocket.js:91 WebSocket connection to 'wss://board.example.com:1234/public-room' failed:

in package.json
"crdt-server": "cd client && HOST=board.example.com PORT=1234 npx y-websocket",
so I'm getting
running at 'board.example.com' on port 1234

and
provider = new WebsocketProvider('wss://board.example.com:1234', roomID, ydoc); in CodeMirrorEditor.tsx
( AWS ports are open for : 1234,3090,5001)

REACT_APP_CLIENT_URL = https://board.example.com:3090 (localhost:3000)
REACT_APP_SERVER_URL = https://board.example.com:5001 (localhost:5000 reverse proxy by Nginx)

&

CLIENT_URL=https://board.example.com:3090
SERVER_URL=http://localhost:5000

socket.io is working fine,
I can see users' join and left notifications, language changes, etc the only issue is code Syncing.

Expected behavior
Code syncing should work in Codemirror.

Desktop (please complete the following information):

• OS: MacOS
• Browser Chrome Version 102.0.5005.115 (Official Build) (arm64)

Please provide your suggestions.