masawada-cast.html

<p><button id="masawada-cast-button" style="display: none">masawada castを開始する</button>
<div id="masawada-cast-button-not-supported" style="display: none">お使いのブラウザは<a href="https://developer.mozilla.org/en-US/docs/Web/API/Presentation_API" target="_blank">Presentation API</a>に対応していないようです</div>
</p>
<script>
  (function () {
    const button = document.querySelector('#masawada-cast-button');
    const error = document.querySelector('#masawada-cast-button-not-supported');
    const show = function () {
      button.style.display = 'block';
    };
    const hide = function () {
      error.style.display = 'block';
    };
    try {
      const request = new PresentationRequest(['https://files.sushi.money/working-masawada.html']);
      navigator.presentation.defaultRequest = request;
      request.getAvailability().then(function (availability) {
        if (!availability) {
          hide();
          return;
        }
        show();
        button.addEventListener('click', function () {
          request.start();
        });
      }).catch(function () {
        hide();
      });
    } catch (error) {
      hide();
    }
  })();
</script>