Sample Google Apps Script that set Slack status emoji and message.

set_slack_status.js

const slackUserId = 'XXXXXXXX'; // your user ID
const slackApiToken = 'xoxp-******-*******-******'; // your API token
const slackSetStatusUrl = 'https://slack.com/api/users.profile.set';

function changeSlackStatus(emoji, message) {
  const headers = {
    'Authorization': 'Bearer ' + slackApiToken,
    'X-Slack-User': slackUserId,
    'COntent-Type': 'application/json; charset=utf-8'
  };
  const payload = {
    'profile': {
      'status_emoji': emoji,
      'status_text': message
    }
  };
  const options = {
    'method': 'post',
    'headers': headers,
    'payload': JSON.stringify(payload)
  };

  const res = UrlFetchApp.fetch(slackSetStatusUrl, options);
  
  const resJson = JSON.parse(res.getContentText());
  console.log(JSON.stringify(resJson, false, 2));
}

function myFunction() {
  changeSlackStatus(':ghost:', 'by Google App Script.');
}