Sepolia test network ID

Question

This is my truffle-config.js

require("babel-register");
const HDWalletProvider = require("truffle-hdwallet-provider");
require("dotenv").config();
module.exports = {
    networks: {
        Sepolia: {
            provider: function() {
                return new HDWalletProvider(
                    process.env.MNEMONIC,
                    process.env.PROJECT_ENDPOINT,
                    address_index=0,
                    num_addresses=2
                );
            },
            network_id: 11155111    ,
             gas: 4500000,
             gasPrice: 10000000000,
        },
        development: {
            host: process.env.LOCAL_ENDPOINT.split(":")[1].slice(2),
            port: process.env.LOCAL_ENDPOINT.split(":")[2],
            network_id: "*",
        },
        compilers: {
            solc: {
                version: "^0.4.24",
            },
        },
    },
};

I am unable to get the network ID for a Sepolia test network. Below is the link of the error I am getting

[ERROR IMAGE][1] [1]: https://i.stack.imgur.com/gBDPN.png

Error: You must specify a network_id in your 'Sepolia' configuration in order to use this network.
at Object.validateNetworkConfig (C:\Users\aditi\AppData\Roaming\npm\node_modules\truffle\build\webpack:\packages\environment\environment.js:136:1)
at Object.detect (C:\Users\aditi\AppData\Roaming\npm\node_modules\truffle\build\webpack:\packages\environment\environment.js:16:1)
at Object.module.exports [as run] (C:\Users\aditi\AppData\Roaming\npm\node_modules\truffle\build\webpack:\packages\core\lib\commands\migrate\run.js:19:1)
at runCommand (C:\Users\aditi\AppData\Roaming\npm\node_modules\truffle\build\webpack:\packages\core\lib\command-utils.js:297:1)

Truffle v5.11.5 (core: 5.11.5) Node v18.17.0