function postApiExample() {
  const url = "https://example.com/api";

  const payload = {
    name: "Yamada",
    age: 30
  };

  const options = {
    method: "post",
    contentType: "application/json",
    payload: JSON.stringify(payload)
  };

  const response = UrlFetchApp.fetch(url, options);
  Logger.log(response.getContentText());
}