I am trying to set a header in static.json on ONLY my index.html file using:

headers: { "/": { "Cache-Control": "no-store" } }

The header works successfully when I specifically go to "https://mywebsite.com/"
But if I go to "https://mywebsite.com/sign-in", the header is not there. This is because /sign-in is not an actual file in my project. It is a route generated by React router.

I know I can use "/**" instead of "/" in static.json, but I don't want to add this header to my .css, .js, fonts etc.

Is there functionality available in static.json to apply headers to only the HTML file, no matter the route?