getting invalid access to property or key 'item1' on a base object of type 'null instance'. in inventory code

[Mohamed_Mahmoud]

Godot Version

4.6.2

why I am gitting invalid access to property or key ‘item1’ on a base object of type ‘null instance’.

note:

hand is node in “main” scene ,, item1 is node in type Dectinary

[wchc]

How do you assign value to hand variable?