I'm making a web app with Google Apps Script. Here's my code:

function doGet(e) {
  return (HtmlService.createHtmlOutputFromFile('index.html'));
}

Whenever I run this I get this error:

Exception: The parameters () don't match the method signature for HtmlService.createHtmlOutputFromFile. (line 2, file "Code")

This is an issue with code, not deployment.