You need at least Rakugo 3.2.1 for this.
Crate new 2D scene or open one to which you want to add clickable areas.
Add MouseBody2D Node to scene
Crate Clickable Area¶
Add AreaButton2D to scene
Add sprite to it if needed
Use CollisionPolygon2D to define clickable area
Should change name of AreaButton2D to more meaning full (In this example I changed it to name to Head)
Extend AreaButton2D script
Now content it to pressed signal
Edit Script as you want in
extends AreaButton2D func _on_Head_pressed(): pass # Replace with function body.
For example if you have Dialogue node attached to this AreaButton2D you can start dialogue like this:
extends AreaButton2D func _on_Head_pressed(): $Dialogue.start("dialogue_event_to_start")