I have a simple backend application built with Node.js.
The directory structure as below

and this is GitHub Repository Link
here below is the code of server.js file

// server.js
const express = require('express');
const bodyParser = require('body-parser');
const dotenv = require('dotenv');
dotenv.config();

const app = express();
const port = process.env.PORT || 3000;

app.use(bodyParser.json());

try {
    // Import routes
    const adminRoutes = require('./routes/adminRoutes');

    // Use routes
    app.use('/api/admins', adminRoutes);  // Correct base URL for admin routes
   
} catch (error) {
    console.log(error);
}

app.listen(port, () => {
    console.log(`Server running on port ${port}`);
});

and redisClient.js file

const redis = require('redis');
const dotenv = require('dotenv');
dotenv.config();

var redisClient;

const initializeRedisClient = () => {
    if (!redisClient) {
        redisClient = redis.createClient();
        redisClient.on('error', (err) => console.log('Redis Client Error:', err));
        redisClient.on('connect', () => console.log('Connected to Redis'));
        redisClient.on('end', () => console.log('Redis client disconnected'));
        redisClient.on('reconnecting', () => console.log('Redis client reconnecting'));
    }
    return redisClient;
};

module.exports = initializeRedisClient;

The issue comes when I try to request API which are using middleware of checkBlacklist.

Below is the issue

C:workshopNode
JSecommerce-apinode_modules@redisclientdistlibclientindex.js:510
return Promise.reject(new errors_1.ClientClosedError());
^

ClientClosedError: The client is closed
at Commander._RedisClient_sendCommand (C:workshopNode JSecommerce-apinode_modules@redisclientdistlibclientindex.js:510:31)
at Commander.commandsExecutor (C:workshopNode JSecommerce-apinode_modules@redisclientdistlibclientindex.js:190:154)
at BaseClass. [as get] (C:workshopNode JSecommerce-apinode_modules@redisclientdistlibcommander.js:8:29)
at checkBlacklist (C:workshopNode JSecommerce-apiroutesadminRoutes.js:14:21)
at Layer.handle [as handle_request] (C:workshopNode JSecommerce-apinode_modulesexpresslibrouterlayer.js:95:5)
at next (C:workshopNode JSecommerce-apinode_modulesexpresslibrouterroute.js:149:13)
at C:workshopNode JSecommerce-apimiddlewaresauthMiddleware.js:13:17
at C:workshopNode JSecommerce-apinode_modulesjsonwebtokenverify.js:261:12
at getSecret (C:workshopNode JSecommerce-apinode_modulesjsonwebtokenverify.js:97:14)
at module.exports [as verify] (C:workshopNode JSecommerce-apinode_modulesjsonwebtokenverify.js:101:10)

It looks like redis client connection is getting lost. Can someone please let me know what should I change in the code?