PWA installation window not showing up in browser - Why? (Vaadin 14)

Hello, I am currently working on a PWA. My current goal is to show up the installation window in the browser but I simply can’t get it. I am not using any example projects from Vaadin or something similar. We run it as a seperated Servlet in one of our projects.

I tried to use as guide.
I am having a valid certificate and use a HTTPS connection to my development application. The following @PWA annotation is used:

@PWA(name = “Test”, shortName = “Test”,
backgroundColor = “#227aef”, themeColor = “#227aef”,
offlinePath = “pwa/offline-page.html”, offlineResources = {“images/logo.png”})
public class MainView extends AppLayout implements RouterLayout, BeforeEnterObserver {

I tried it with Chrome and Firefox, both didn’t show an installation window.

It is mentioned that Vaadin creates a Web App Manifest and ServiceWorker by its own ( but I cant find it anywhere after my project is build. Where are they stored and how can I check that they are created?

Edit: I could verifiy that my application does not start a Service Worker in Firefox. …/sw.js does not find a worker.

What am I missing here?

There’s some related discussion in this thread: - can you check it out?

I tried the Vaadin Bakery App (built and executed it on my machine, and everything worked fine. I was able to install the App and use it locally.

I have the issue that no ServiceWorker is created, I think. The @PWA annotation is used once in my application but I can’t find the ServiceWorker anywhere. Firefox (where the Bakery App worked fine, ServiceWorker was activated) also does not show any ServiceWorker or manifest from my application (same in Chrome).

Chrome lighthoues tests tells me that no service worker is found, same for the manifest. @PWA is used in my application. Any ideas? Vaadin throws no exception or something similar.