Why doesn't my javascript work?

Shopify Discussion
8 
document.addEventListener("DOMContentLoaded", function() {
  const input = document.getElementbyId("schriftzug");
  const log = document.getElementById("schrift");

  input.addEventListener("input", updateValue);

  function updateValue(e) {
    log.textContent = e.target.value;
  }
});

This worked wonderfully, it was using the first input field it found, not the one I wanted!