How to use the eth-sig-util.TypedDataUtils function in eth-sig-util

// dicether/eip712
// eth-sig-util
// eth_sig_utils.signTypedData
// eth_sig_utils.recoverTypedSignature
// https://github.com/MetaMask/eth-sig-util#signtypeddata-privatekeybuffer-msgparams
// https://github.com/MetaMask/eth-sig-util#signtypeddata-privatekeybuffer-msgparams

var w3_utils = require("web3-utils");
var eth_sig_utils = require("eth-sig-util");
var eth_accounts = require("web3-eth-accounts");
var eth_util = require("ethereumjs-util");
const utils = eth_sig_utils.TypedDataUtils;

var buyer_key = "0x" + "a4985a2ed93107886e9a1f12c7b8e2e351cc1d26c42f3aab7f220f3a7d08fda6";
var buyer_key_bytes = w3_utils.hexToBytes(buyer_key);
const consumer_key = '0x395df67f0c2d2d9fe1ad08d1bc8b6627011959b79c53d7dd6a3536a33ab8a4fd';
const consumer_delegate_key = '0xe485d098507f54e7733a205420dfddbe58db035fa577fc294ebd14db90767a52';

var account = new eth_accounts().privateKeyToAccount(consumer_key);
var addr = eth_util.toBuffer(account.address);

console.log("Using private key: " + buyer_key);
//console.log(buyer_key_bytes);
//console.log(account);
console.log("Account canonical address: " + account.address);
//console.log(addr);

const data3 = {