I am working on Google sheets Addon and want to create custom menu outside Addon menu something like below:
Expected output
Actual output
I found that it only works for Container-bound Scripts but not for Addon.
It's not possible.
According to the documentation, this is only possible for unpublished add-ons, but even when testing the add-on, the top-level menus gets moved into the Add-ons menu.
Caution: Unpublished add-ons can also create custom top-level menus, but these are automatically moved under the Add-ons menu if the add-on is published and may not result in the user experience you intended. If you intend to publish the add-on, always use Ui.createAddonMenu() to define the add-on menu.