this is my code

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

module.exports = async function ({ deployments, getNamedAccounts }) {
    const { deployer } = await getNamedAccounts();
    const { deploy, log } = deployments;
    let VRFCoordinatorV2Address, subscriptionId;
    const chainId = network.config.chainId;
    const VRF_SUB_AMOUNT = ethers.parseEther("2");
    const entranceFee = networkConfig[chainId]["entranceFee"];
    const gasLane = networkConfig[chainId]["gasLane"];
    const callbackGasLimit = networkConfig[chainId]["callbackGasLimit"];
    const interval = networkConfig[chainId]["interval"];

    if (deploymentChains.includes(network.name)) {
        const VRFCoordinator = await ethers.getContract("VRFCoordinatorV2Mock");
        VRFCoordinatorV2Address = VRFCoordinator.address;
        const transactionResponse = await VRFCoordinator.createSubscription();
        const transactionReceipt = await transactionResponse.wait(1);
        subscriptionId = transactionReceipt.events[0].args.subId;
        await VRFCoordinator.fundSubscription(subscriptionId, VRF_SUB_AMOUNT);
    } else {
        VRFCoordinatorV2Address = networkConfig[chainId]["VRFCoordinatorAddress"];
        subscriptionId = networkConfig[chainId]["subscriptionId"];
    }

    const args = [
        VRFCoordinatorV2Address,
        entranceFee,
        gasLane,
        subscriptionId,
        callbackGasLimit,
        interval,
    ];
    const raffle = await deploy("Raffle", {
        from: deployer,
        log: true,
        args: args,
        waitConfirmations: network.config.blockConfirmations,
    });
    if (!deploymentChains.includes(network.name) && process.env.ETHERSCAN_API_KEY) {
        await verify(raffle.address, args);
    }
    log("----------------------------------------------");
};

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

this is the error im getting

i have noticed that the error is coming from the line [subscriptionId = transactionReceipt.events[0].args.subId;] can anyone tell me why its happening.

and this is the smart contract code

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@chainlink/contracts/src/v0.8/VRFConsumerBaseV2.sol";
import "@chainlink/contracts/src/v0.8/interfaces/VRFCoordinatorV2Interface.sol";
import "@chainlink/contracts/src/v0.8/AutomationCompatible.sol";

/*errors*/
error Raffle__NotEnoughETHentered();
error Raffle__TransferFailed();
error Raffle__NotOpen();
error Raffle__upKeepNotNeeded(uint256 balance, uint256 numPlayers, uint256 raffleState);

contract Raffle is VRFConsumerBaseV2, AutomationCompatibleInterface {
    enum RaffleState {
    OPEN,
    CALCULATING
    }

    uint256 private immutable i_entranceFee;
    address payable[] private s_players;
    uint256 private s_requestId;
    bytes32 private immutable i_gasLane;
    uint64 private immutable i_subscriptionId;
    uint16 private constant REQUEST_CONFIRMATIONS = 3;
    uint32 private immutable i_callbackGasLimit;
    uint32 private constant NUM_WORDS = 1;
    VRFCoordinatorV2Interface private immutable i_vrfcoordinator;

    /*lottery variables*/
    address private s_recentWinner;
    RaffleState private s_raffleState;
    uint256 private s_lastTimeStamp;
    uint256 private immutable i_interval;

    /*Events*/
    event RaffleEnter(address payable indexed player);
    event RequestedRaffleWinner(uint256 requestId);
    event WinnerPicked(address indexed Winner);

    /*Functions*/
    constructor(
        address VRFCoordinatorV2,
        uint256 entranceFee,
        bytes32 gasLane,
        uint64 subscriptionId,
        uint32 callbackGasLimit,
        uint256 interval
) VRFConsumerBaseV2(VRFCoordinatorV2) {
        i_entranceFee = entranceFee;
        i_vrfcoordinator = VRFCoordinatorV2Interface(VRFCoordinatorV2);
        i_gasLane = gasLane;
        i_subscriptionId = subscriptionId;
        i_callbackGasLimit = callbackGasLimit;
        s_raffleState = RaffleState.OPEN;
        s_lastTimeStamp = block.timestamp;
        i_interval = interval;
    }

    function enterRaffle() public payable {
        if (msg.value < i_entranceFee) {
            revert Raffle__NotEnoughETHentered();
        }
        if (s_raffleState != RaffleState.OPEN) {
            revert Raffle__NotOpen();
        }

        s_players.push(payable(msg.sender));
        emit RaffleEnter(payable(msg.sender));
    }

    function checkUpkeep(
    bytes memory /*checkData*/
) public override returns (bool upkeepNeeded, bytes memory /*performData*/) {
        bool isOpen = (RaffleState.OPEN == s_raffleState);
        bool timePassed = (block.timestamp - s_lastTimeStamp > i_interval);
        bool hasBalance = (address(this).balance > 0);
        bool hasPlayers = (s_players.length > 0);
        upkeepNeeded = (isOpen && timePassed && hasBalance && hasPlayers);
    }

    function performUpkeep(bytes calldata /*performData*/) external override {
        (bool upkeepNeeded, ) = checkUpkeep("");
        if (!upkeepNeeded) {
            revert Raffle__upKeepNotNeeded(
                address(this).balance,
                s_players.length,
                uint256(s_raffleState)
            );
        }
        s_raffleState = RaffleState.CALCULATING;
        s_requestId = i_vrfcoordinator.requestRandomWords(
            i_gasLane,
            i_subscriptionId,
            REQUEST_CONFIRMATIONS,
            i_callbackGasLimit,
            NUM_WORDS
        );
        emit RequestedRaffleWinner(s_requestId);
    }

    function fulfillRandomWords(
        uint256 /*requestId*/,
        uint256[] memory randomWords
) internal override {
        uint256 indexOfWinner = randomWords[0] % s_players.length;
        address payable recentWinner = s_players[indexOfWinner];
        s_recentWinner = recentWinner;
        (bool success, ) = recentWinner.call{value: address(this).balance}("");
        s_players = new address payable[](0);
        s_lastTimeStamp = block.timestamp;
        if (!success) {
            revert Raffle__TransferFailed();
        }
        emit WinnerPicked(recentWinner);
        s_raffleState = RaffleState.OPEN;
    }

    /*view/pure functions*/
    function getEntranceFee() public view returns (uint256) {
        return i_entranceFee;
    }

    function getPlayer(uint256 index) public view returns (address) {
        return s_players[index];
    }

    function getRecentWinner() public view returns (address) {
        return s_recentWinner;
    }

    function getRaffleState() public view returns (RaffleState) {
        return s_raffleState;
    }

    function getNumWords() public pure returns (uint32) {
        return NUM_WORDS;
    } 

    function getNumOfPlayers() public view returns (uint256) {
        return s_players.length;
    }

    function getLatestTimeStamp() public view returns (uint256) {
        return s_lastTimeStamp;
    }

    function getRequestConfirmations() public pure returns (uint16) {
        return REQUEST_CONFIRMATIONS;
    }
}