after deployment in live server, 404 error occurs on refresh of urls

-> i made an admin dashboard in React and built it for production
-> but after i build, the problem is that when I navigate to another page and hit refresh, an error occurs saying Cannot GET /login
-> after deployment in live server(using Filezilla), 404 error occurs on refresh of URLs

URL: https://demo.templatesjungle.com/admin/

I think the problem is this:
it's probably because i've built an SPA and haven't set up any redirects in your host
You'll need to redirect every route on your server back to / for an SPA to work.
what do I do? How do I do this?

app.js: