handler

 let string = '';
 let counter = 0;
 const start = async () => {
    await Promise.all(data.Contents.map(async element => {
        string += await someAsyncFunc(element);
        console.log('Counter: ' + counter);
        counter++;
    }))
    console.log('Finishing');
    doSomethingAfterThat(string);
}

start();

async function someAsyncFunc(data: string) {
  return new Promise((resolve, reject) => {
      //wait....
      resolve('asd');
  })
}