How to make a option for changing currency?

const balance = document.getElementById("balance");
const money_plus = document.getElementById("money-plus");
const money_minus = document.getElementById("money-minus");
const list = document.getElementById("list");
const form = document.getElementById("form");
const text = document.getElementById("text");
const amount = document.getElementById("amount");
const localStorageTransactions = JSON.parse(localStorage.getItem("transactions"));

let transactions = localStorage.getItem("transactions") !== null ? localStorageTransactions : [];

function addTransaction(e) {
  e.preventDefault();
  if (text.value.trim() === "" || amount.value.trim() === "") {
    alert("Please add text and amount :D");
  } else {
    const transaction = {
      id: generateID(),
      text: text.value,
      amount: +amount.value,
    };

    transactions.push(transaction);

    addTransactionDOM(transaction);
    updateValues();
    updateLocalStorage();
    text.value = "";
    amount.value = "";
  }
}

function generateID() {
  return Math.floor(Math.random() * 1000000000);
}

function addTransactionDOM(transaction) {
  const sign = transaction.amount < 0 ? "-" : "+";
  const item = document.createElement("li");

  item.classList.add(transaction.amount < 0 ? "minus" : "plus");

  item.innerHTML = `${transaction.text} <span>${sign}${Math.abs(transaction.amount)}</span><button class="delete-btn" onclick="removeTransaction(${transaction.id})">x</button>`;
  list.appendChild(item);
}

function updateValues() {
  const amounts = transactions.map((transaction) => transaction.amount);
  const total = amounts.reduce((acc, item) => (acc += item), 0).toFixed(2);
  const income = amounts
    .filter((item) => item > 0)
    .reduce((acc, item) => (acc += item), 0)
    .toFixed(2);
  const expense = (
    amounts.filter((item) => item < 0).reduce((acc, item) => (acc += item), 0) *
    -1
  ).toFixed(2);

  balance.innerText = `₹${total}`;
  money_plus.innerText = `₹${income}`;
  money_minus.innerText = `₹${expense}`;
}

function removeTransaction(id) {
  transactions = transactions.filter((transaction) => transaction.id !== id);
  updateLocalStorage();
  Init();
}

function updateLocalStorage() {
  localStorage.setItem("transactions", JSON.stringify(transactions));
}

function Init() {
  list.innerHTML = "";
  transactions.forEach(addTransactionDOM);
  updateValues();
}

Init();

form.addEventListener("submit", addTransaction);

<h2>Expense Tracker</h2>
<div class="container">
  <h4>Your Balance</h4>
  <h1 id="balance">₹0.00</h1>
  <div class="inc-exp-container">
    <div>
      <h4>Income</h4>
      <p id="money-plus" class="money-plus">+₹0.00</p>
    </div>
    <div>
      <h4>Expense</h4>
      <p id="money-minus" class="money-minus">-₹0.00</p>
    </div>
  </div>

  <h3>History</h3>
  <ul id="list" class="list"></ul>
  <h3>Add New Transaction</h3>
  <form id="form">
    <div class="form-control">
      <label for="text">Text</label>
      <input type="text" id="text" placeholder="Enter Text...." autocomplete="off" />
    </div>
    <div class="form-control">
      <label for="amount">
        Amount <br />
        (- for expense , + for income)
      </label>
      <input type="number" id="amount" placeholder="Enter amount..." autocomplete="off" />
    </div>
    <button class="btn">Add transaction</button>
  </form>
</div>