How can i track how many users are downloading a file?

addEventListener("fetch", event => {
  event.respondWith(fetchAndStream(event.request))
});

async function fetchAndStream(request) {
    // Fetch from origin server.
    let response = await fetch("https://speed.hetzner.de/10GB.bin", request);

    return new Response(response.body)
}

addEventListener("fetch", event => {
  event.respondWith(fetchAndStream(event.request))
});

async function fetchAndStream(request) {
    // Fetch from origin server.
    let response = await fetch("https://speed.hetzner.de/10GB.bin", request);

    return new Response(response.body)
}