This is my current server.js.

import path from 'path';
import cors from 'cors';
import nocache from 'nocache';
import express from 'express';
import mongoose from 'mongoose';
import { fileURLToPath } from 'url';
import bodyParser from 'body-parser';
import Router from './routes/index.js';
import PaymentController from './controllers/client/payment.controller.js';

// Get the directory name of the current module
const __dirname = path.dirname(fileURLToPath(import.meta.url));

mongoose.connect(process.env.DB)
    .then(() => {
        console.log(`Database connected successfully ${process.env.DB}`);
    })
    .catch((error) => console.log(error));

const app = express();

app.use(nocache());

// Combine to frontend for production
if (process.env.MODE == 'production') {
    app.use(express.static(path.join(__dirname, '../production/build')));
} else if (process.env.MODE == 'staging') {
    app.use(express.static(path.join(__dirname, '../staging/build')));
}

const allowedOrigins = [
    'http://localhost:3000'
];

const corsOptions = {
    origin: function (origin, callback) {
        if (!origin) return callback(null, true);
        if (allowedOrigins.indexOf(origin) !== -1) {
            callback(null, true);
        } else {
            callback(new Error('Not allowed by CORS'));
        }
    },
    methods: 'GET, OPTIONS',
    allowedHeaders: ['Content-Type', 'Authorization'],
    credentials: true,
};

// Apply CORS to most routes
app.use(cors(corsOptions));

app.post('/v1/api/webhook', express.raw({ type: 'application/json' }), PaymentController.handleSubscriptionEvent);

app.use(
    bodyParser.json({
        limit: '15360mb',
        type: 'application/json',
    })
);

app.use(
    bodyParser.urlencoded({
        limit: '15360mb',
        extended: true,
        parameterLimit: 5000000,
        type: 'application/json',
    })
);

app.use('/v1/', Router);

// Combile to frontend for production
if (process.env.MODE == 'production') {
    app.get('*', (req, res) => {
        res.sendFile(path.resolve(__dirname, '../production/build', 'index.html'));
    });
} else if (process.env.MODE == 'staging') {
    app.get('*', (req, res) => {
        res.sendFile(path.resolve(__dirname, '../staging/build', 'index.html'));
    });
}

const port = process.env.MODE === 'production' || process.env.MODE === 'staging' ? 3000 : 9200;
const runningMessage = 'Server is running on port ' + port;

app.listen(port, () => {
    console.log(runningMessage);
});

This is Router

import express from 'express';
import AdminRouter from './admin.router.js';
import ClientRouter from './client.router.js';
import ServiceRouter from './service.router.js';

const router = express.Router();

router.use('/api/admin', AdminRouter);
router.use('/api', ClientRouter);
router.use('/api/service', ServiceRouter);

export default router;

I want to allow CORS for almost routes from allowedorigins. But about the special routes, I want to access them from any origins. I mean, I want to allow CORS for the special routes from any origins. The speical router is /v1/api/service.

How can I do it in Node.js/Express backend?