Have problems while running Lemmy locally. Please help

I want to develop custom front end for Lemmy. I've compiled and run a local version of backend but when I started front end it was not able to connect to websocket.

2023-05-29T21:34:22.394558Z INFO actix_web::middleware::logger: 127.0.0.1 "GET /api/v3/ws HTTP/1.1" 404 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/113.0.0.0 Safari/537.36" 0.000167

websocket.js:80 WebSocket connection to 'ws://localhost:8536/api/v3/ws' failed: Websocket.tryConnect @ websocket.js:80 eval @ websocket.js:114 WebSocketService.ts:43 Websocket closed.