Using FeePayer on web3 solana token swap?

I am using javascript from github to create a solana SPL token swap, but I want to use feepayer to pay the transaction fee, I am a beginner, can you explain how to implement it? I have attached the script code and the original github link. Thank you for your help.

import { Keypair } from "@solana/web3.js";import bs58 from "bs58";import { SolanaTracker } from "../";async function swap() {  const keypair = Keypair.fromSecretKey(    bs58.decode("YOUR_SECRET_KEY_HERE"    )  );  const solanaTracker = new SolanaTracker(    keypair,"https://rpc.solanatracker.io/public?advancedTx=true"  );  const swapResponse = await solanaTracker.getSwapInstructions("So11111111111111111111111111111111111111112", // From Token"4k3Dyjzvzp8eMZWUXbBCjEvwSkkk59S5iCNLY3QrkX6R", // To Token    0.0001, // Amount to swap"auto", // Slippage    keypair.publicKey.toBase58(), // Payer public key"auto", // Priority fee (Recommended while network is congested)  );  // Jito transaction  try {    const txid = await solanaTracker.performSwap(swapResponse, {      sendOptions: { skipPreflight: true },      confirmationRetries: 30,      confirmationCheckInterval: 500,      commitment: "processed",      jito: {        enabled: true,        tip: 0.0001,      },    });    // Returns txid when the swap is successful or throws an error if the swap fails    console.log("Transaction ID:", txid);    console.log("Transaction URL:", `https://solscan.io/tx/${txid}`);  } catch (error: any) {    const {signature, message} = error;    console.error("Error performing swap:", message, signature);  }}swap();