Call function with signal on other scene

Question

I'm still getting confused as how to call a function from another script on another scene in Godot 4.x. In my example below, I want to call print_something() on menu.tscn from main.tscn

On main scene we have:

# main.gd
# main.tscn
extends Node2D

func _ready():
    print_something("Hello") #works on main

func print_something(astring):
    print(astring)

On menu scene we have:

# menu.gd
# menu.tscn
extends Node2D
signal mysignal
@export var message := "Gwen Stefani is bananas!"
# main.print_something(message) # Unexpected "Identifier" in class body.

When trying to connect the signal node I'm not given the option of picking another scene.

Undated script as Alex CB suggested still results in error: extends Node2D

extends Node2D
# menu.tscn
@onready var main := get_tree().root.get_node("main")
@export var message := "Gwen Stefani is bananas!"
# then you can use
main.print_something(message)

Answer 1

To connect a signal by code, you do like this:

var err := main.connect("signal_name", callable_name)

But, for what I understand you want to do, you don't need a signal. According to the official documentation:

(signals) should be used only to "respond" to behavior, not start it. By convention, signal names are usually past-tense verbs like "entered", "skill_activated", or "item_collected".

Another way could be to access main from the menu, like this:

@onready var main := get_tree().root.get_node("main")
# or, if menu is a direct child of main
@onready var main := get_parent()


@export var message := "Gwen Stefani is bananas!"
# then you can use inside a function 
func _ready():
  main.print_something(message)

Also, you'll have to instance menu scene in your main scene by clicking the Instance child scene (chain icon, top left, next to the + symbol).