What exactly are you having trouble with? It's not much different than any other clickable interactable object.
If dialogue is waiting for response
On 1 clicked, do something
On 2 clicked, do something
On 3 clicked, do something
On 4 clicked, do something
Although for most classic rpgs, they all actually do the same thing, which is to advance the dialogue anyway.
I need to learn mechanics not for one question but whole conversation for each NPC.
Where store all texts for each NPC.
Better use event sheet only or JSON ?
Better use 4 text objects for each dialog option or its possible to use only one text object to display all 4 dialog options?