Automatically trigger actions
You can automatically trigger an action or a sequence of actions without involving a user’s action.
Some actions do not require the user, such as triggering the automatic animation of the home screen. To do this, you have some triggers available: Current Screen Display & Current State Display.
To choose these triggers and set up your action, go to your screen/state and do not select any object. Open the Actions window and click + Add.
Select the Current Screen/State Display trigger and set your action.

All the triggers are detailed here: Triggers