Add Service Worker to HTML

index-script.html

<script>
  if ('serviceWorker' in navigator) {
    navigator.serviceWorker.register('/service-worker.js')
      .then(function (registration) {
        console.log('Service Worker registration successful with scope: ', registration.scope)
      })
      .catch(function (err) {
        console.log('Service Worker registration failed: ', err)
      })
  }
</script>