Resolve Quiz Website Sitemap/Indexing Issues

I have a quiz website built with React + Vite and hosted on Firebase Hosting.

The website is fully developed and working, but I am facing a serious Google Search Console sitemap/indexing issue.

Problem:

* Google Search Console shows:

* “Sitemap could not be read”
* “Couldn’t fetch”
* Pages are not getting indexed properly.
* Sitemap opens in browser, but Google still cannot fetch/read it correctly.

Website type:
This is a public current affairs quiz website for exams like UPSC, SSC, Banking, Railways, etc.

What I need:

* Fix sitemap issue completely.
* Fix Google indexing issue.
* Verify sitemap works properly with Googlebot.
* Configure Firebase Hosting correctly for sitemap and robots.txt.
* Optimize SEO setup for React SPA.
* Ensure homepage and public quiz pages can be indexed properly.
* Remove/noindex private pages like dashboard/login if needed.
* Verify everything in Google Search Console after fixing.

Tech stack:

* React + Vite
* Firebase Hosting
* React Router
* Firebase Firestore/Auth

Important:
The website is already completed. I do NOT want a redesign or rebuild. I only need sitemap, indexing, Firebase hosting, and SEO-related fixes.