Is it not standard for the Blizz UI to show healing numbers done on a friendly target? I dont see any

[whatisgoingon 0]

is there no way to display Healing Numbers on a friendly target, without addons, just like red dmg numbers on an enemy target?

I am pretty sure there was. A guy in the chat whispered me as an answer simply "interface" and didnt reply further. In the interface, where is there the option to turn on shown green healing numbers on a friendly target?

[Athene 3]

You can't :)