it works

globals/game_manager.gd

@@ -0,0 +1,14 @@
+extends Node
+
+var score: int  = 0
+var  sl = null
+
+func set_label(label:Label):
+	score = 0
+	sl = label
+	
+func add_point():
+	score+=1
+	sl.text	="You got " + str(score) + " coins"
+	print(score)
+