I am trying to create a mobile add-in with Office.js and I am using OnNewMessageCompose event.

10 second after event launched, I am trying to get body with the code below but it doesnt work.

async function getEmailBody() {
    return new Promise((resolve) => {
      setTimeout(() => {
          Office.context.mailbox.item.body.getAsync(Office.CoercionType.Html, function (asyncResult) {
              if (asyncResult.status == "failed") {
                    resolve(null);
                  } else {
                    resolve(asyncResult.value);
                  }
                });
    });

  }, 10 * 1000);
}

async function newMessageCompose(event) {
  await getEmailBody()
  event.completed();
}

It immidiatly goes error and mail body has value its not empty. It Work with Web and Desktop application but not with mobile