Use Vanilla Selectors In Commands

To be honest I doubt any other plugin has this feature implemented. It means that I would have to recognize, somehow, that you're using this particular Minecraft vanilla command execute as and replace the placeholders correctly.

To get vanilla selectors working in ItemsAdder commands you have to install PsudoCommands.

Example:

/execute at (player) run psudo iaentity summon (entity) ~ ~ ~ world