<div id="products">
  <label>
    <input type="checkbox" id="items" value="хлеб">
    хлеб
  </label>
    <label>
    <input type="checkbox" id="items" value="хлеб2">
    хлеб 2
  </label>
    <label>
    <input type="checkbox" id="items" value="хлеб3">
    хлеб 3
  </label>
    <label>
    <input type="checkbox" id="items" value="хлеб4">
    хлеб 4
  </label>
</div>

const products = [...document.querySelectorAll("#items")];

document.querySelector("#products").addEventListener("change", () => {
  const result = products.filter(item => item.checked).map(item => item.value);
  alert(result);
});