Can't find serviceWorker in navigator anymore

Serve your page over HTTPS or use localhost. Service workers require a Secure Context.

(MDN page, Chromium page).

The value of window.isSecureContext indicates whether [SecureContext] features are visible or hidden. (This is true on a file:// URL and the serviceWorker API will be visible, but it won't work, of course.)

If you are using a virtual host locally for a domain other than localhost, you can tell chrome to treat your custom domain as "secure".

In the addressbar: chrome://flags/#unsafely-treat-insecure-origin-as-secure

Then add your domain like http://my-local-dev-domain.test

Click enable and click the restart button.

Another reason might be running a browser in private-mode