script needed Pickup Messages?

[BiggusWeeabus]

So, there's a mod for Reborn and Rejuvenation that changes the behavior of the ability Pickup to show a message whenever your Pokémon picks up an item and then automatically stores it in the bag.

This is a great QoL feature that i want to implement in my own game, but i need to know how and where to modify the ability.

 

Thank you in advance :)