Netlify Website Working well except QR codes linked to the site result in 404 Page Not Found

No it doesn’t. I just tried.

It is not redirects.txt the filename is _redirects. And you haven’t mentioned what it is you apparently put in the file.

Was it something like this?

/*   /index.html  200

As mentioned in [Support Guide] Direct links to my single page app (SPA) don't work