addProduct.js

function addProduct(id) {
  let cart = JSON.parse(localStorage.getItem("products")) || [];

  const foundItem = cart.find((product) => product.id === id);
 
  if (foundItem) {
    foundItem.quantidade++;
  } else {
    cart.push({ id: id, qtd: 1 });
  }

  localStorage.setItem("products", JSON.stringify(cart));
}