LESSON 9 All tests passed, except for the last pickWinner, Error reason: Error: VM Exception while processing transaction: reverted with custom error 'InsufficientBalance()'

[jupiter-Pulin]

error is this:await VRFCoordinatorV2_5Mock.fulfillRandomWords(requestId, Raffle.address);

it("picks a winner, resets, and sends money", async () => {
    const additionalEntrances = 3;
    const startindex = 1; // first account == 0
    const accounts = await ethers.getSigners();
    const VrfFundAmount = ethers.utils.parseEther("1000");

    // Simulate many people entering the raffle
    for (let i = 1; i < startindex + additionalEntrances; i++) {
        await Raffle.connect(accounts[i]).enterRaffle({
            value: ethers.utils.parseEther("1"),
        });
    }

    // Use a promise to wait for the WinnerPicked event
    await new Promise(async (resolve, reject) => {
        Raffle.on("WinnerPicked", async () => {
            console.log(`WinnerPicked event detected!!!`);
            try {
                const endBlockTimeStamp = await Raffle.getLatestTimeStamp();
                raffleState = await Raffle.getRaffleState();
                
                // Assert the raffle state is OPEN after the winner is picked
                assert.equal(raffleState, 0); // 0 means OPEN state
                assert(endBlockTimeStamp > blockTimeStamp);
                resolve();
            } catch (e) {
                reject(e);
            }
        });

        console.log(`Starting raffle process`);

        const blockTimeStamp = await Raffle.getLatestTimeStamp();
        const raffleTx = await Raffle.performUpkeep("0x");
        const raffleReceipt = await raffleTx.wait();

        // Capture events
        const event = raffleReceipt.logs
            .filter((log) => log.address === VRFCoordinatorV2_5Mock.address) // Filter logs from VRFCoordinatorV2Mock
            .map((log) => {
                try {
                    return VRFCoordinatorV2_5Mock.interface.parseLog(log);
                } catch (e) {
                    return null;
                }
            })
            .filter((event) => event && event.name === "RandomWordsRequested")[0];

        if (event) {
            // Extract the requestId from the event
            requestId = event.args.requestId;
            console.log(`requestId: ${requestId}`);
        } else {
            // If RandomWordsRequested event is not found, throw an error
            throw new Error("RandomWordsRequested event not found");
        }

        console.log(`Initiating random word fulfillment`);

        try {
            // Call fulfillRandomWords with the requestId
            await VRFCoordinatorV2_5Mock.fulfillRandomWords(requestId, Raffle.address);
        } catch (e) {
            console.error("Error calling fulfillRandomWords:", e); // I don't know where the error is, maybe I can come back later to check this
        }
    });
});

[jupiter-Pulin]

please tell me what wrong with this