test/example-sw.html

<!DOCTYPE html>
<html>
  <head>
    <title>SW test</title>
    <script src="https://unpkg.com/pokeapi-js-wrapper/dist/index.js"></script>
  </head>

  <body>
    <script>
      const P = new Pokedex.Pokedex({ cacheImages: true });
    </script>
    <div id="app">
      <img
        src="https://raw.githubusercontent.com/PokeAPI/sprites/master/sprites/pokemon/other/dream-world/25.svg"
        alt="Pikachu"
      />
    </div>
    <div>
        The above image is served (once cached) by the local <i>pokeapi-js-wrapper-sw.js</i> SW. Check it out in the Developer Console (F12) by looking at the Network Panel and also at the Application Panel.
    </div>
  </body>
</html>