PWA Toolkit and debugging service worker/cache

I created a PWA using

I am trying to debug the service worker / cache locally using Developer tools, locally I cannot see the service worker or anything loaded into the cache. When I deploy the app to a server, I can see the service worker and cache be populated. Any ideas?

There are several images I’ve added to a list of items displayed on the main screen that I want to be cached via loading from the service worker.