Azure Static website react.js getting 404 in the browser but returning the correct content on a path

Question

So like I normally setup static websites, with error page going back to index.html. The browser response shows a 404 though, on local it works ok and shows a 200. I'm not sure if this is an issue with the reactjs router or the azure static website configuration. Anyway to send this back as a 200
in my console shows

GET https://app.testsite.com/signup 404
Navigated to https://app.testsite.com/signup

and then works ok. Some browsers have issue with this as it shows red in the console

Answer 1

Ah, I see this is solved by a CDN rewrite rule, having this over the azure storage 404 redirect, I found this here,

https://antbutcher.medium.com/hosting-a-react-js-app-on-azure-blob-storage-azure-cdn-for-ssl-and-routing-8fdf4a48feeb

at the SpaRewriteRules