> Using querySelectorAll

btnSubmit.addEventListener('click', function handleClick(event) {
  event.preventDefault();
  const els = document.querySelectorAll('#email, #password');
  els.forEach(element => {
    element.value = '';
  });
});

> Using Form

const form = document.getElementById('your_form_id');
form.addEventListener('submit', function handleSubmit(event) {
  event.preventDefault();
  form.reset();
});