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>

We recommend having your roof inspected at least once a year to ensure it’s in good condition and to catch any potential issues early. We also recommend scheduling a roof inspection after severe weather events or if you notice any signs of damage in order to address any problems as soon as possible.