Configuring Rails to Use react-router

I am currently thinking of creating a SPA with Rails as the backend.

I would like to control the /user screen below when I log in using the browserHistory of react-router.
In other words, whether you access /user/hoge, or /user/fuga, Rails always takes the same action, and we would like to draw using React on the client side.

I'm looking for a lot of things.
I found a way to define the /user/hoge and /user/fuga actions on the controller and use the same view for both.
Note: https://github.com/sugyan/react-router-scaffold

It is true that even if the react-router changes the URL, it can be reloaded.
But I think this is a bit redundant.

If you increase the number of routes on the client side, you must configure the same route on the server side.

So I tried to see if nginx could do something like the one described in react-router.
Note: https://github.com/reactjs/react-router/blob/master/docs/guides/Histories.md#configuring-your-server

 location/user/{
  try_files$uri/user;
}

After a lot of trial and error, when I wrote it like this, it worked as I wanted.

Now that I've come to that point, I'm wondering if I should use nginx, so I'm going to ask you a question now.

Is it impossible for Rails to set up a route that performs the specified action without issuing 404 no matter what requests are received below /user?
Or is there a gem that can be done?