no i found the solution. for me its
(pblock means popup)
var Pblock = preload("res://Popup4.tscn")
(i added a timer so when its timeout, it will play this method)
Random:
var Pblock_instance = Pblock.instance()
Pblock_instance.set_position(Vector2(rand_range(-200,200), rand_range(-100, 200)))
add_child(Pblock_instance)