How to preload data before rendering react app

i use React location library. Want to get token from cookie if it exist then send it to server to check if it is active. My question is how i can do this once before rendering app regardless of route?

i`ve tried something like this but it works only for specific route

    {
        path: '/',
        element: () => import('../pages/Main').then(mod => <mod.default />),
        loader: async () => {
            return {
                user: await fetchResource('user', {}, true)
            };
        }
    },

In App.js you could do something like this

const [ready, setReady] = useState(false);
useEffect(()=>{
  // fetch your token and verify
  setReady(true)
  },[]);

return (
  {
    ready ? (
      // Your app components here
    ) : (
       <div> Loading .... </div>
    )
  }
)