function getFavs() {
  let favList = [];
  const inputs = document.querySelectorAll('input');
  for (const input of inputs) {
    if (input.checked === true) {
      favList.push(input.parentNode.textContent);
    }
  }
  document.querySelector('.favorites').textContent = favList.join(' ');
}

let button = document.querySelector('button');

button.addEventListener('click', getFavs);