How to use vite plugin $env or $lib alias in Svelte project

I'm using the Svelkit project.When importing modules from Sveltkit, path aliases such as $lib and $env are often used.

However, when using a separate vite plugin that is not included within the Sveltkit project, I would like to use an alias such as $env or $lib used in the Sveltkit when importing environment variables or js files.

Below is what I tried, but it doesn't work.

What am I doing wrong?

vite.config.js

import { sveltekit } from '@sveltejs/kit/vite';import { defineConfig } from 'vite';import path from 'path';import socketHandler from './src/lib/server/socketHandler/socketHandler.js';const webSocketServer = {    name: 'webSocketServer',    configureServer(server) {        if (!server.httpServer) return;        socketHandler(server.httpServer);    }}export default defineConfig({    plugins: [sveltekit() , webSocketServer()],        resolve: {            alias: {'$lib': path.resolve(__dirname, './src/lib'),'$env': path.resolve(__dirname, '.'),            },          },});

socketHandler.js

import { Server } from 'socket.io';import login from '$lib/login.js';import {DB_PASSWORD} from '$env/static/private';import disconnect from '$lib/disconnect.js';// other imports...global.userCode = {};export default function socketHandler(server) {    const db_pass=DB_PASSWORD;    const io = new Server(server);    const onConnection = (socket) => {        reconnect(io, socket);         disconnect(io, socket);        login(io, socket);         orderRequest(io, socket);        // ...    }    io.on("connection", onConnection);}

npm run dev

failed to load config from C:\home\lcare_renewal\vite.config.jserror when starting dev server:Error [ERR_MODULE_NOT_FOUND]: Cannot find package '$lib' imported from C:\home\lcare_renewal\vite.config.js.timestamp-1727503166699-f59eaa69482cd.mjs    at new NodeError (node:internal/errors:405:5)    at packageResolve (node:internal/modules/esm/resolve:890:9)    at moduleResolve (node:internal/modules/esm/resolve:939:20)    at defaultResolve (node:internal/modules/esm/resolve:1132:11)    at nextResolve (node:internal/modules/esm/loader:163:28)    at ESMLoader.resolve (node:internal/modules/esm/loader:835:30)    at ESMLoader.getModuleJob (node:internal/modules/esm/loader:424:18)    at ModuleWrap.<anonymous> (node:internal/modules/esm/module_job:77:40)    at link (node:internal/modules/esm/module_job:76:36)