Wanting to add timer to confirm selection of object (Rock Paper Scissors)

Hi folks, I'm working on recreating the classic Rock Paper Scissors scenes seen in Alex Kidd in Miracle World, and what I'd like to do is figure out how to add a timer so that when the time runs out it keeps the choice I made between Rock Paper and Scissors. I've got a large amount of the code (taken from an awesome course on how to make a basic Rock Paper Scissors game courtesy of Canopy Games) and help from some lovely people in Adelaide Game Developer discord on how to scroll between scenes for the player as well.

Once I can figure that out, I'll look at how to get the opponent to show their choice. Code and screenshots as follow:

Globals.gd (autoload name is gl in case you wonder why so much "gl"'ing going on in the code:

extends Node
var rock = preload("res://Scenes/rock.tscn")
var paper = preload("res://Scenes/paper.tscn")
var scissors = preload("res://Scenes/scissors.tscn")
var array = [rock, paper, scissors]
var objidx:int = 0
var currobjref

player.gd:

extends CharacterBody2D
@onready var janken_container = $JankenContainer
func _process(delta):
    if Input.is_action_just_pressed("up"):
        _scroll(1)
    elif Input.is_action_just_pressed("down"):
        _scroll(-1)
func _scroll(delta: int) -> void:
    gl.objidx = (gl.objidx+delta) % gl.array.size()
    var newobj = gl.array[gl.objidx].instantiate()
    if (gl.currobjref):
        gl.currobjref.queue_free()
    gl.currobjref = newobj
    janken_container.add_child(newobj)
    newobj.global_position = global_position
    newobj.global_position.x += 0
    newobj.global_position.y -= 60

and opponent.gd:

extends Node2D
@onready var jankenoppcontainer = $jankoppcontainer
var delay:float = 0.5
var possible_choices:Array[String]
var opponent_choice
var player_choice
var timer_stage:int = 0
func _ready():
    possible_choices = [gl.rock, gl.paper, gl.scissors]
func _process(delta):
    if Input.is_action_just_pressed("ui_up"):
        opponent_scroll(1)
    elif Input.is_action_just_pressed("ui_down"):
        opponent_scroll(-1)    
 func opponent_scroll(delta: int) -> void:
    gl.objidx = (gl.objidx+delta) % gl.array.size()
    var newobj = gl.array[gl.objidx].instantiate()
    if (gl.currobjref):
        gl.currobjref.queue_free()
    gl.currobjref = newobj
func display_opponent_choice(jankenoppcontainer):
    jankenoppcontainer.show
    player_choice = jankenoppcontainer
    pick_action()
    print("You picked " + player_choice)
    await get_tree().create_timer(delay).timeout
    check_winner()
    await get_tree().create_timer(delay).timeout
    jankenoppcontainer.add_child(gl.newobj)
    gl.newobj.global_position = global_position
    gl.newobj.global_position.x += 0
    gl.newobj.global_position.y -= 60
func pick_action():
    randomize()
    opponent_choice = possible_choices[randi() % possible_choices.size()]
func check_winner():
    if player_choice == gl.rock and opponent_choice == gl.scissors:
        player_wins()
    elif player_choice == gl.paper and opponent_choice == gl.rock:
        player_wins()
    elif player_choice == gl.scissors and opponent_choice == gl.paper:
        player_wins()
    elif player_choice == opponent_choice:
        tie()
    else:
        opponent_wins()
func player_wins():
    print("You Win!")
func opponent_wins():
    print("You Lose!")
func tie():
    print("It's a Tie!")