Change
<div
  id="loc-name"
></div>
<div
  id="loc-phone-number"
></div>

<script>
  window.onload = function() {
    // Retrieve the value from sessionStorage
    var locationNumber = sessionStorage.getItem('location_phone_number');

    // Check if the value is not null
    if (locationNumber) {
      // Set the inner HTML of the div to a clickable link with tel href
      document.getElementById('loc-phone-number').innerHTML = '<a href="tel:' + locationNumber + '">' + locationNumber + '</a>';
    }
  };
</script>

Your asphalt shingle roofing cost depends on your roof’s size and complexity, the shingles you choose, and its current condition. We provide an upfront estimate so you know the cost before moving forward.