An example that demonstrates how to get random numbers from chainlink

Chainlink-RNG.sol

// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.8;
pragma experimental ABIEncoderV2;

import "@chainlink/contracts/src/v0.8/VRFConsumerBase.sol";

contract Example is VRFConsumerBase {

  //   on Rinkeby Network
  address __vrfCoordinatorAddress  = 0xb3dCcb4Cf7a26f6cf6B120Cf5A73875B7BBc655B;
  address __linkTokenAddress       = 0x01BE23585060835E02B77ef475b0Cc51aA1e0709;
  bytes32 __oracleKeyhash          = 0x2ed0feb3e7fd2022120aa84fab1945545a9f2ffc9076fd6156fa96eaff4c1311;
  
  uint256 fee;
  bytes32 keyHash;
  
  event Something(uint256 ok);

  constructor() VRFConsumerBase(__vrfCoordinatorAddress, __linkTokenAddress) public {

      keyHash = __oracleKeyhash;

      fee = 0.1 * 10 ** 18; // 0.1 Link
      
  }
  
  function getRandomNumber(uint256 userProvidedSeed) public returns (bytes32 requestId) {
      return requestRandomness(keyHash, fee);
  }
  
  function fulfillRandomness(bytes32 requestId, uint256 randomness) internal override {
    
    emit Something(randomness);
  }
  
}