Why does URL change, React Router?

Question

React

There is such a link: name.github.io/example, example is removed when entering the site, that is, from this one:
name.github.io/example
It turns into this:
name.github.io
I need what would happen when the page is refreshed was name.github.io/example.
Here is an example: an example , I went to the site: domen/taskreactive/, and when the page is updated, there is no page, because /taskreactive/ disappears
. problem?

router:

// импорты
  import {
    Route,
    BrowserRouter as Router,
    Switch
  } from 'react-router-dom';

// разметка
     <Router>
        <div style={{ display: "flex", justifyContent: "center" }}>
          <PageHeader />
            <Switch>
              <Route path="/profile">
                <Profile />
              </Route>
              <Route path="/">
                <NewUser />
                <Home />
              </Route>
            </Switch>
          </div>
        </div>
      </Router>

Answer 1

https://muffinman.io/blog/react-router-subfolder-o...
As far as I remember githab pages allow you to create a subdomain for a subfolder in the repository, by right clicking on it. Perhaps this solution will be simpler than the one described above