I want to write a function which will return below statement. The function is writen in .ts file. I am new to type script and still learning it.

function intitalizeApp() {    

  <React.StrictMode>
    <Loading />
  </React.StrictMode>,
  document.getElementById('root')
  
}

The problem i am facing is that show me red underline but the same code work fine when i am putting in .tsx file.

Please click to see the image

Can anybody point me why i am seeing red line when i am putting in .ts file or there is any other issue?