Hardhat Lottery : deployer undefined when deploy on Rinkeby

[LeNooooooo]

In lesson 9 (hardhat Lottery), after the test, when I try to deploy on Rinkeby, I've got the following error :

Error: ERROR processing D:\coding-center-main\harhat-lottery\deploy\01-deploy-raffle.js:
TypeError: Cannot read properties of undefined (reading 'length')

After digging (putting some console.log to know which variable is undefined), I've found that it's the variable deployer that is undefined.

01-deploy-raffle.js :

const { network, ethers } = require("hardhat")
const { developmentChains, networkConfig } = require("../helper-hardhat-config")
const { verify } = require("../utils/verify")

module.exports = async ({ getNamedAccounts, deployments }) => {
    const { deploy, log } = deployments // same than declaring deployments.deploy and deployments.log
    const { deployer } = await getNamedAccounts()
    const chainId = network.config.chainId
    let vrfCoordinatorV2Address, subscriptionId
    const VRF_SUB_FUND_AMOUNT = ethers.utils.parseEther("2")

    if (developmentChains.includes(network.name)) {
        const vrfcoordinatorV2Mock = await ethers.getContract("VRFCoordinatorV2Mock") // establish the connexion to the mock contract here
        vrfCoordinatorV2Address = vrfcoordinatorV2Mock.address

        //below we programmatically create a subscription on chainlinkCRF by using some function

        const transactionResponse = await vrfcoordinatorV2Mock.createSubscription()

        const transactionReceipt = await transactionResponse.wait(1) // wait one block

        subscriptionId = transactionReceipt.events[0].args.subId // here we grab the subscription id from an event who was generated by the contract vrf

        await vrfcoordinatorV2Mock.fundSubscription(subscriptionId, VRF_SUB_FUND_AMOUNT) // here we suscribe VRF, with amount define above
    } /*meaning we are not on a devchain but on testnet or mainnet*/ else {
        vrfCoordinatorV2Address = networkConfig[chainId]["vrfCoordinatorV2"] // syntaxe to call the chainlink contract address present in helper-hardhat-config
        console.log("vrf coordinator address : " + vrfCoordinatorV2Address)
        subscriptionId = networkConfig[chainId]["subscriptionId"] //calling the data in the helper
        console.log("subscription id : " + subscriptionId)
    }

    const entranceFee = networkConfig[chainId]["entranceFee"]
    console.log("Entrance Fee : " + entranceFee)
    const arg = []
    console.log("Arg: " + arg)
    const gasLane = networkConfig[chainId]["gasLane"]
    console.log("Gas Lane : " + gasLane)
    const callbackGasLimit = networkConfig[chainId]["callbackGasLimit"]
    console.log("callback gas limit : " + callbackGasLimit)
    const interval = networkConfig[chainId]["interval"]
    console.log("interval : " + interval)

    console.log("deployer: " + deployer)

    const raffle = await deploy("Raffle", {
        from: deployer,
        args: [
            vrfCoordinatorV2Address,
            entranceFee,
            gasLane,
            subscriptionId,
            callbackGasLimit,
            interval,
        ],
        log: true,
        waitConfirmations: network.config.blockConfirmations || 1,
    })

    console.log("Raffles : " + raffle)

    // if we are not on dev chain (hardhat) we verify with the code below
    if (!developmentChains.includes(network.name) && process.env.ETHERSCAN_API_KEY) {
        log("Verifying the contract on Etherscan....")
        await verify(raffle.address, arg)
    }
    log("------------------------------------")
}

module.exports.tags = ["all", "raffle"]

hardhat.config.js file :

require("@nomiclabs/hardhat-waffle")
require("@nomiclabs/hardhat-etherscan")
require("hardhat-deploy")
require("solidity-coverage")
require("hardhat-gas-reporter")
require("hardhat-contract-sizer")
require("dotenv").config()

/** @type import('hardhat/config').HardhatUserConfig */

const RINKEBY_RPC_URL = process.env.RINKEBY_RPC_URL
const PRIVATE_KEY = process.env.PRIVATE_KEY
const COINMARKETCAP_API_KEY = process.env.COINMARKETCAP_API_KEY
const ETHERSCAN_API_KEY = process.env.ETHERSCAN_API_KEY

module.exports = {
    defaultNetwork: "hardhat",
    networks: {
        hardhat: {
            chainId: 31337,
            blockConfirmations: 1,
        },

        rinkeby: {
            chainId: 4,
            blockConfirmations: 6,
            url: RINKEBY_RPC_URL,
            account: PRIVATE_KEY,
        },
    },

    gasReporter: {
        // this will generate a gaz report .txt file
        enabled: false,
        outputFile: "gas-report.txt",
        noColors: true,
        currency: "USD",
        //coinmarketcap: COINMARKETCAP_API_KEY,
        //token: "ETH",
    },

    solidity: "0.8.8",
    namedAccounts: {
        deployer: {
            default: 0,
            1: 0,
        },
        player: {
            default: 1,
        },
    },

    mocha: {
        timeout: 300000, // 200 Seconds max
    },
}

helper-hardhat-config.js file :

const { ethers } = require("hardhat")

const networkConfig = {
    4: {
        name: "rinkeby",
        vrfCoordinatorV2: "0x6168499c0cFfCaCD319c818142124B7A15E857ab", // this is the coordinator chainlink adress
        // for rinkeby, can be found here : https://docs.chain.link/docs/vrf/v2/supported-networks/
        entranceFee: ethers.utils.parseEther("0.01"), // definition of the entrance fee on rinkeby
        gasLane: "0xd89b2bf150e3b9e13446986e571fb9cab24b13cea0a43ea20a6049a85cc807cc", // this is the 30 Gwey hash (only one) in the rinkkeby docs
        // can be found here : https://docs.chain.link/docs/vrf/v2/supported-networks/

        subscriptionId: "19476", // this number is the subcription id from chainlik VRF

        callbackGasLimit: "500000",

        interval: "30",
    },

    31337: {
        name: "hardhat",
        // no vrfcoordinator because we use the mock
        entranceFee: ethers.utils.parseEther("0.01"),
        gasLane: "0xd89b2bf150e3b9e13446986e571fb9cab24b13cea0a43ea20a6049a85cc807cc",
        callbackGasLimit: "500000",
        interval: "30",
    },
}

const developmentChains = ["hardhat", "localhost"]

module.exports = {
    networkConfig,
    developmentChains,
}

The .env file is filled with the good RPC link from alchemy, and the private key is the one from my metamask, connected to rinkeby.

Can somebody please explain to me where is the mistake. And I don't really understand how the named account work (what 0: and 1: means exactly)

Thanks very much for your answer.

[othaime-en]

There is an error in your hardhat.config file in the rinkeby section.
account: PRIVATE_KEY should be accounts: [PRIVATE_KEY]

[othaime-en]

Okay if you have multiple accounts in you accounts sections for example here you have four accounts in the rinkeby section.

rinkeby: {
            chainId: 4,
            blockConfirmations: 6,
            url: RINKEBY_RPC_URL,
            accounts: [PRIVATE_KEY_1, PRIVATE_KEY_2, PRIVATE_KEY_3, PRIVATE_KEY_4]
        },

So if you write

deployer: {
            default: 0,
            1: 0,
        }

You are saying that you are setting the default account to be account at index 0 which in this case, we will link the name deployer to PRIVATE_KEY_1. If you want to use the second account with PRIVATE_KEY_2 you can write default: 1 (We start counting from 0 so first is 0, second is 1)
However, you can also set specific accounts to specific chains. So in the second line 1: 0 we are saying that for ethereum mainnet (which has chainId 1) we are also setting the default account to be account at index 0 which is PRIVATE_KEY_1

[othaime-en]

Here is the documentation. https://www.npmjs.com/package/hardhat-deploy
Read the namedAccounts section

[LeNooooooo]

Sorry i just see your answer. By account on index 0, you mean the private account on the 0 position in accounts?

[othaime-en]

Yes, the account on 0 position of this accounts array [PRIVATE_KEY_1, PRIVATE_KEY_2, PRIVATE_KEY_3, PRIVATE_KEY_4]

[LeNooooooo]

Thanks very much for all your answers :)