Speak to Npc and destroy actor

I have dialogue widget blueprints in third person as it is the only way I know how to do it but what I am having problem with still is I want to be able to collect an item such as coins only after spoken to a npc not just anytime. How would I go about doing This? Could you please help with what I would put in which graph? Even images would be helpful. I need step by step if possible or just images

The easiest way i can think of is to create a boolean variable inside the character bp/class and set it to true after you have talked to npc. after that make a condition which will only allow you to pickup the item if the variable is true.

so for example in blueprints: if you are using a trigger box, on the actor begin overlap check if the variable is true using a “branch” node and then do the rest of the logic using the true execution pin in the branch.

I still dont understand how to do this can someone show me an example of how i would set this up if i have dialogue widgets with a npc and then destroy a certain item. if i dont speak to the npc i cant destroy the bp