google cloud function node js. not parsing arabic data

Question

Cloud function for data sync from Firebase to mysql not recognizig arabic data. error showing after sending arabic data. generated logs below

my cloud function code is below:

const functions = require('firebase-functions');
const https = require('https')

exports.myFunction = functions.firestore
  .document('distri/{docId}')
  .onWrite((change, context) => { 
    reqstatus = true;

    // console.log(change);
    //console.log(context);

    //console.log(change.after.data());

    obj = {};
    obj.id = context.params.docId;
    obj.table = 'distri';
    obj.data = change.after.data();
    data = JSON.stringify(obj);
    console.log(data);

    options = {
    hostname: 'xyz.com',
    port: 443,
    path: '/app',
    method: 'POST',
    headers: {
    'Content-Type': 'application/json; charset=UTF-8',
    'Content-Length': data.length,
    'Content-Encoding': 'utf-8'
    }
    }

  const req = https.request(options, res => {
  console.log(`statusCode: ${res.statusCode}`)

  res.on('data', d => {
  process.stdout.write(d)
  })
  })

  req.on('error', error => {
  console.error(error)
  reqstatus = false;
  })

  req.write(data)
  req.end()

  return reqstatus;

});

Api is working fine when it recieves data in english. API is based on simple php which insert data into MYSQL.