How to create an automation where the trigger is checking off an item on a checklist

[Karla Frias]

and the action is: Adding a new item to a current to-do list on another card, then added a due date two weeks from the trigger date, and assigned to a certain team member.  

So far the first picture is what I have: 

But it creates the checklist "Foundation To Do:  in the original card and adds the item, due date, and member.  I need to go to another existing card that already has that checklist of the same name. 

I've also tried not specifying the card to see if it will look in the entire board, but I still get the same results. 

Any tips would be greatly appreciated! Thank you!