After generating sitemap (XML) it has only one link in it

I need to make a sitemap for website squad.in.ua. I've tried to generate it by online sitemap-generators and also made a generator in my React app to generate it automatically. The result is the same:

<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.sitemaps.org/schemas/sitemap/0.9 http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd">
<url>
<loc>http://squad.in.ua/</loc>
<lastmod>2020-02-17T17:39:02+00:00</lastmod>
</url>
</urlset>

Website is written on React with react-router technology. Router contains as static web pages, so as dynamic created pages, but doesn't generate any.

function Routes() {
  return (
    <Switch>
        <Route exact path="/" component={HomePage}/>
        <Route exact path="/projects" component={Projects}/>
        <Route exact path="/project" component={Project}/>
        <Route exact path="/blog" component={Blog}/>
        <Route exact path="/blog/:sortId" component={Blog}/>
        <Route exact path="/blog/article/:articleId" component={Blog}/>
        <Route exact path="/job" component={Job}/>
        <Route exact path="/contact" component={Contact}/>
    </Switch>
  );
}

What could be the problem of generating only one url in sitemap?