To get vanilla selectors working in ItemsAdder commands you have to install PsudoCommands.
Example:
/execute at (player) run psudo iaentity summon (entity) ~ ~ ~ world
ItemsAdderTo get vanilla selectors working in ItemsAdder commands you have to install PsudoCommands.
Example:
/execute at (player) run psudo iaentity summon (entity) ~ ~ ~ world