Building an iOS shot clock App with multiple timers and sounds

Question

I have made a countdown timer which I will use for pool tournaments as a shot clock and I have managed to add a sound for when the timer reaches 5 seconds left but I wanted another sound to be played at 5 seconds down to 1 second and also a separate sound at 0 seconds which I’ve dragged over to my sidebar and I have working functions for start/stop/extension etc.

I tried using one single audio file that I stitched together to run from 5 seconds to make it easier but I found a problem that when the shot clock reaches 5 and it starts to play that file and if I push the stop/restart button then it will simply pause the audio file and then when the next shot clock countdown reaches 5 seconds the file begins from the point that it was stopped "paused" so just wanted to ask if there was a line of code that I can add to my current code to reset the stitched single audio file that I have or play a single sound for each second 5 to 0?

for reference, I'm a beginner at using Xcode :)

Here is where I am currently.

Shot Clock App

//
//  ViewController.swift
//  Shot Clock 5
//
//  Created by Marcus Allen on 16/03/2022.
//

import UIKit
import AVFoundation
import SwiftUI

class ViewController: UIViewController, UITextFieldDelegate{

    var seconds = 30
    var timer = Timer()
    var audioPlayer = AVAudioPlayer()
    var count = 0

    @IBOutlet weak var label: UILabel!

    
    @IBOutlet weak var sliderOutlet: UISlider!
    @IBAction func slider(_ sender: UISlider)
    {
        seconds = Int(sender.value)
        label.text = String(seconds)
        
    }
    
    @IBAction func name2(_ sender: UITextField) {
        sender.resignFirstResponder()
    }
    
    @IBAction func name1(_ sender: UITextField) {
        sender.resignFirstResponder()
    }
    
    @IBAction func score2(_ sender: UITextField) {
        sender.resignFirstResponder()    }
    
    @IBAction func score1(_ sender: UITextField) {
        sender.resignFirstResponder()
    }
    
    
    @IBOutlet weak var startOutlet: UIButton!
    @IBAction func start(_ sender: Any)
    {
        timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(ViewController.counter), userInfo: nil, repeats: true)
        
        sliderOutlet.isHidden = true
        startOutlet.isHidden = true
    }
    
    @objc func counter()
    {
        seconds -= 1
        label.text = String(seconds) + ""

        if (seconds == 0)
        {
            timer.invalidate()
        }
        
        if (seconds == 5)
        {
            
            do {

        }
            
            sliderOutlet.isHidden = false
            startOutlet.isHidden = false
            
            audioPlayer.play()
        }
    }
    
    @IBAction func EXT2(_ sender: UIButton) {seconds += 15    }
    @IBAction func ext2pressed(_ sender: UIButton) {
        sender.backgroundColor = sender.backgroundColor == UIColor.red ? UIColor.black : UIColor.red    }
    
    @IBAction func EXT1(_ sender: UIButton) {seconds += 15    }
    @IBAction func ext1pressed(_ sender: UIButton) {
        sender.backgroundColor = sender.backgroundColor == UIColor.red ? UIColor.black : UIColor.red
    }
    
    
    @IBOutlet weak var stopOutlet: UIButton!
    @IBAction func stop(_ sender: Any)
    {
        timer.invalidate()
        seconds = 30
        sliderOutlet.setValue(30 , animated: true)
        label.text = "30"
        
        audioPlayer.stop()
        
        sliderOutlet.isHidden = false
        startOutlet.isHidden = false
    }
    
    override func viewDidLoad()
    {
        super.viewDidLoad()
        
        do
        {
            let audioPath = Bundle.main.path(forResource: "3", ofType: ".mp3")
            try audioPlayer = AVAudioPlayer(contentsOf: URL(fileURLWithPath: audioPath!))
        }
        catch {
            //ERROR
        
        }
    }
}