Hello DevForum!
Today I want uncopylock simple custom dialogue System.
I Hope You Like It.
Link: Custom Dialouge System - Roblox
Suggestions:
Q: I need give credits?
A: Nope! Feel Free To Use
Q: How To I change Keybind?
A: First Go StarterGui.NPCText.TextGiver 
And Set Your Keybind! Don’t Forget Edit StarterGui.DetectorPopUp.Key.Text