Using backgroundFetch in pwa.

[felek]

Hello i want to try backgroundFetch in my pwa app.
The final idea is to have array of object with links and some additional data and store them in indexdb. I did that using axios.
However i would like to try that with backgroundFetch.
In config:

workboxPluginMode: "InjectManifest",
workboxOptions: {},

Now my: custom-service-worker

import { precacheAndRoute } from "workbox-precaching";
import { register } from "register-service-worker";
import { newContentAvailable } from "src/services/notification/notyfication";
import { i18n } from "boot/i18n";

precacheAndRoute(self.__WB_MANIFEST);
console.log("custom sw11");

register(process.env.SERVICE_WORKER_FILE, {
  updated(/* registration */) {
    console.log("New content is available; please refresh.bzzzz");
    newContentAvailable(i18n.t("newContentAvailable"));
  },
});

self.addEventListener("backgroundfetchsuccess", (event) => {
  console.log("[Service Worker]: Background Fetch Success", event.registration);
});
self.addEventListener("backgroundfetchfail", (event) => {
  console.log("backgroundfetchfail", event);
});

self.addEventListener("backgroundfetchabort", (event) => {
  console.log("backgroundfetchabort", event);
});

self.addEventListener("install", (event) => {
  console.log("install", event);
});

However when i build app and deploy i can see message from: register-service-worker.js

Service worker is active.
Service worker has been registered.

When in dev tools i unregister it i get new messages from custom-service-worker . However when refresh again thaere is back that 2 messages above. Then when i start download file:

  navigator.serviceWorker.ready.then(async (swReg) => {
    console.log("swReg", swReg.backgroundFetch);
    const bgFetch = await swReg.backgroundFetch.fetch(
      "my-fetch",
      ["url"],
      {
        title: "index",
        // icons: [
        //   {
        //     sizes: "300x300",
        //     src: "/ep-5-icon.png",
        //     type: "image/png",
        //   },
        // ],
        downloadTotal: 512,
      }
    );

…
It never finish and event only fire backgroundfetchabort

Any one know maybe why ?