transaction fails when I call getRandomNumber() function from chainlink VRF v1 - blockchain

Question

I am using chainlink VRF v1 to get a random number. I am using ethers.js to call the getRandomNumber() function but it always fails with this message: Error: transaction failed [ See: https://links.ethers.org/v5-errors-CALL_EXCEPTION ]
I have enought LINK in my contract so that is not the reason for this. Is there any other possible or anything wrong with my code?
my smart contract:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.12;
import "#chainlink/contracts/src/v0.8/VRFConsumerBase.sol";
contract VRFConsumer is VRFConsumerBase {
bytes32 keyHash;
uint256 requiredFee;
uint256 public randomResult;
constructor()
VRFConsumerBase(
0x844ECf0B33EB65e1EC34AEa0d082D39879169890,
0xa36085F69e2889c224210F603D836748e7dC0088
)
{
keyHash = 0x6c3699283bda56ad74f6b855546325b68d482e983852a7a82979cc4807b641f4;
requiredFee = 0.1 * 10**18;
}
function getRandomNumber() public returns (bytes32 requestId) {
require(
LINK.balanceOf(address(this)) >= requiredFee,
"Not enough LINK - fill contract with faucet"
);
return requestRandomness(keyHash, requiredFee);
}
function fulfillRandomness(
bytes32, /*requestId*/
uint256 randomness
) internal override {
randomResult = randomness;
}
}
my frontend code:
const provider: ethers.providers.Web3Provider = new ethers.providers.Web3Provider((window as any).ethereum;
);
const signer: ethers.providers.JsonRpcSigner = provider.getSigner();
const vrfConsumer = new ethers.Contract(
this.address,
vrfConsumerABI,
provider
);
console.log("Start");
const vrfConsumerWithSigner = vrfConsumer.connect(signer);
const tx = await vrfConsumerWithSigner.getRandomNumber({
gasPrice: 3000000000,
gasLimit: 2000000,
});
await tx.wait();
const result: BigNumber = await vrfConsumer.randomResult();
console.log(result.toNumber());
console.log("done");

Answer 1

I suggest you to check some functions in Chainlink hardhat-starter-kit
helper-functions.js
tasks\random-number-consumer\request-random-number.js
tasks\random-number-consumer\read-random-number.js