Of course it's not under Settings -> Appearance where the similar "Show quick copy actions on vault" option is. Why should an option that only affects the UI be in "appearance".
Because it barely changes the appearance at all? The actual effect of that setting is to change the behavior of the button to be autofill. The only visual change is that the small "Fill" button is removed.
These are screenshots from the extension, before and after checking that autofill box. The only visual change is the missing "Fill" button, because now clicking on the item itself preforms the fill action. The rest of the UI looks exactly the same.
