How to trigger a function when dialog choice is selected?

I was making a NPC that had some dialog and he would offer you an item. If the player clicked yes, the script was supposed to find an item from ServerStorage and put it in their Backpack. The only problem is that every tutorial I try says to use "DialogChoiceSelected" but Output says "DialogChoiceSelected is not a valid member if DialogChoice". Was testing to see if it worked by deleting the option when it was selected so the player could only say no, but I got the error in Output and the option didn't disappear. Here's the script:

local d = script.Parent
d.DialogChoiceSelected:Connect(function()
	d:Destroy()
end)

I know this is not a request site but I have no idea how to do this.