To call an enum, you call its parent class, name, and property. For example,
FormApp.DestinationType.SPREADSHEET.
// Open a form by ID and create a new spreadsheet.
var form = FormApp.openById('1234567890abcdefghijklmnopqrstuvwxyz');
var ss = SpreadsheetApp.create('Spreadsheet Name');
// Update the form's response destination.
form.setDestination(FormApp.DestinationType.SPREADSHEET, ss.getId());
Properties
Property
Type
Description
SPREADSHEET
Enum
A Google Sheets spreadsheet as a destination for form responses.