expo build web a page path

I have make a project with expo.

It works fine and I'm very happy, but now I need to access directly to a subpage (such as https://example.com/backoffice)

In the App.js I have make this:

...
const linking = {
    prefixes: ['https:/example.com'],
    config: {
      screens: {
        Home: '',
        Backoffice: '/backoffice',
      }
    },
  };

  return (
    <NavigationContainer linking={linking}>
...

If I execute the code in develop mode and I call the site to :19006 port, I can access directly to subpages.

If I execute the code after expo build:web and npx serve web-build I can't access to subpage (I receive a 404 not found).