I just inherited a website where the whole site (including index.html) is cached by a service worker. I deleted the old website and migrated it to WordPress. The problem is that when users visit this website they still see the old site and I don't have a way to clear the cache.

I tried adding headers to Nginx Cache-Control "no-store, must-revalidate"; expires 0; but this had no effect since index.html page was not loaded from the server but directly from service worker cache.

It seems that there is no way for me to update this site at all. Old users are seeing the old version no matter what I do. Is there any way I can disable this service worker or force clear the cache at this point?