After right-click --> new Batch Drawable Import and selecting any .png from the Select Image Asset(s) box, the primary Batch Drawable
There were multiple issues preventing operation of this plugin in later releases of Android Studio.
Forked, fixed and tested under Android Studio 3.6 RC 1.
Guinea pigs may download the plugin installation zip from here.
( AS -> Settings -> Plugins -> Install from disk )
Tip: Uninstall the old version beforehand.