Iframe With Service Worker

b.html

<script>
  onload=e=>{
    document.open()
    document.write(`<script src=b.js><\/script>`)
    document.close()
  }
</script>

index.html

<iframe id=abc></iframe>
<script>
const {serviceWorker} = navigator
serviceWorker.register('service-worker.js')
.then(serviceWorker.ready)
  .then(reg=>{
  document.getElementById('abc').src='b.html'
  })
</script>

service-worker.js

onfetch=e=>console.log(e.request.url)