- Edited
The simplest is sceneTreeTimer:
https://docs.godotengine.org/en/stable/classes/class_scenetreetimer.html
However I don't use it because it's not part your scene and might cause issues. Better to create a Timer, and then "await timer.timeout" (edit: and usually better to put code in the timer callback, than using await, await is more for some situations usually where you are awaiting a special signal). If you build the Timer into your scene with the editor and make a unique name, that will simplify it much more than doing it with code.
TBH Godot should have a time argument to call_deferred() , that would simplify a lot