const ssml = `
<speak>
  <lang xml:lang="ja-JP">
    ${text}
  </lang>
</speak>
`;

const res = await fetch("http://alexa_api:3500/speak", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    device,
    ssml
  }),
});