onlinesim.js

const rp = require('request-promise-native');

async function getTzId(apiKey) {
  const response = await rp({
    url: `https://onlinesim.ru/api/getNum.php?apikey=${apiKey}&service=other`,
    method: 'GET',
  });
  // 97833
  if (response.response === 1) {
    return response.tzid;
  } else {
    throw new Error(response.response);
  }
}

const apiKey = 'apiKey';

getTzId(apiKey).then((result) => {
  console.log("result", result);
}).catch(error => {
  console.log("error", error);
});