Add item to existing menu in Google Apps Script
Currently it is not possible. Even though the documentation says
A document, spreadsheet, or form can only contain one menu with a given name. If the same script or another script adds a menu with the same name, the new menu will replace the old.
when I tried the following code
DocumentApp.getUi().createMenu('Tools')
.addItem('Tool_item', 'toolItem')
.addToUi();
another Tools menu was created:
Yes and no.
Yes, you can add your menu ONLY into the existing 'Add-ons'.
No, but nowhere else other than your own customized menu.
The code below may help:
function onOpen(e) {
var ui = SpreadsheetApp.getUi();
// Or DocumentApp or FormApp.
ui.createAddonMenu()
.addItem('Sort Current Column with Header until Blank Rows', 'sortCurrentColumn')
.addToUi();
}
function onInstall(e) {
onOpen(e);
}
You can do what you want with custom menus (add, combine...) but you can't in any way modify built in menus, they are not accessible from Google-Apps-Script.