code.gs

```
var runSelect = true
function onSelectionChange(e) {
  var sheet = SpreadsheetApp.getActiveSheet()
  var range = e.range;
  var column = range.getColumn();
  var lastRow = sheet.getLastRow();
  var ui = SpreadsheetApp.getUi();
  if (runSelect == true) {
    sheet.getRange(5, column, lastRow-4).activate();
    sheet.getRange(1, column).copyTo(sheet.getActiveRange());
    ui.alert("Finnish")

```

I have try to change my selection, but alert never show and not do copy
['https://Stackoverflow.com/questions/61929649', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/13578315/']
This works pretty good and it can also be used for people that have wanted to trigger an event when clicking on a cell in past questions.

```
function onSelectionChange(e) {
  var sh=e.range.getSheet();
  e.source.toast('Sheet: ' + sh.getName() + ' Range: ' + e.range.getA1Notation());  
}

```
According to <https://developers.google.com/apps-script/reference/base/ui.html> alert(prompt) does not require authorization. Probably the onSelectionChange trigger is not executed and you are using the new V8 runtime. Use the legacy runtime, not the V8 runtime. With V8 runtime in my case sometimes it is triggered, sometimes not. There are general problems with trigger executions in V8, see <https://issuetracker.google.com/issues/147016387>