fetch/private-network-access/resources/service-worker-fetch-all.js

self.addEventListener("install", () => {
    // Skip waiting before replacing the previously-active service worker, if any.
    // This allows the bridge script to notice the controller change and query
    // the install time via fetch.
    self.skipWaiting();
});

self.addEventListener("activate", (event) => {
    // Claim all clients so that the bridge script notices the activation.
    event.waitUntil(self.clients.claim());
});

self.addEventListener("fetch", (event) => {
  const url = new URL(event.request.url).searchParams.get("proxied-url");
  if (url) {
    event.respondWith(fetch(url));
  } else {
    event.respondWith(fetch(event.request));
  }
});