How is it possible to access homepage from package.json in a react app?

I created a react app that will be served from /example-path. I defined it in the package.json like this:

"homepage":"/example-path"

It has worked so far, but now I would like to add routing with react-router-dom, and it incorrectly detects /example-path as the part of the URL.

This is my code:

<Router>
  <Switch>
    <Route path="/product/:id" children={<DisplayProduct />} />
  </Switch>
</Router>

Unfortunately react-router-dom tries to match the full URL /example-path/product/10. How is it possible to avoid that? Is it possible to access the homepage variable somehow?

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I could use <Router basename="/example-path">, but in that way, this parameter is a duplicate. I would like to define it in only one place.

from How is it possible to access homepage from package.json in a react app?