Use Bootstwatch Materia theme
// public/index.html
<link
rel="stylesheet"
href="https://cdn.jsdelivr.net/npm/bootswatch@4.5.2/dist/materia/bootstrap.min.css"
/>
Trying bootstrap css
// App.js
export default function App() {
return (
<div>
<h1 className="display-1 bg-primary text-light p-5">App</h1>
</div>
);
}