OnEdit Trigger to update whenever any change is made

How can I make this trigger every time I make any edit to my Google Sheet?

function addNote() {  var ss = SpreadsheetApp.getActiveSpreadsheet();  var sheet = ss.getSheets()[0];  var targetCell = sheet.getRange("A1");  var sourceCell = sheet.getRange("Setup & Statements!B1");  var noteText = sourceCell.getValue();  targetCell.setNote(noteText);}