"SPA Server" is a NodeJS library that starts a production ready NodeJS Webserver, that mostly serves static files and also allows you to manipulate any non-static response (for example HTTP Headers and meta tags).
If a service worker is used it could be that the index.html is used as a navigation fallback.
I guess the best thing would be to have an "empty" index.html in the app cache as a fallback
If a service worker is used it could be that the index.html is used as a navigation fallback. I guess the best thing would be to have an "empty" index.html in the app cache as a fallback