JSFiddle - React, Tailwind, and code Playground

HTML

<body>
  <nav>
    <ol>
      <li>Home</li>
      <li>About</li>
      <li>Contact</li>
    </ol>
  </nav>
</body>

CSS

ol li {
  list-style: none;
  display: inline;
}

ol li::after {
  content: '|';
}

/*
https://stackoverflow.com/questions/2351623/combining-css-pseudo-elements-after-the-last-child
*/
ol li:last-child::after {
  content: '';
}