Why is my dropdown not able to control my game countdown time?

System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class Timer : MonoBehaviour
{
public static float timeMax = StartTime;

public bool timerIsRunning = false;
public Text timeText;


public Dropdown DropdownTimer;
public bool pick = false;

public static float StartTime;
private float PickTime;

public bool check = false;

public void Start()
{
    // Starts the timer automatically
    timerIsRunning = true;
}

public void Play()
{
    if (check == false)
    {
        StartTime = 60;
    }
    else
    {
        StartTime = PickTime;
    }

}

public void Drop()
{
    switch (DropdownTimer.value)
    {
        default:
            PickTime = 60;
            check = true;
            break;
        case 1:
            PickTime = 30;
            check = true;
            break;
        case 2:
            PickTime = 45;
            check = true;
            break;
        case 3:
            PickTime = 60;
            check = true;
            break;
    }
}

public void Update()
{
   
    timeText.text = ("Time: " + PickTime.ToString());
    if (timeMax == 0)
    {
        timeMax = PickTime;
    }
    if (timerIsRunning)
    {
        if (timeMax > 0)
        {
            timeMax -= Time.deltaTime;
            DisplayTime(timeMax);
        }
        else
        {
            Debug.Log("Time has run out!");
            timeMax = 0;
            timerIsRunning = false;
        }
    }

   

}

void DisplayTime(float timeToDisplay)
{
    timeToDisplay += 1;

    float minutes = Mathf.FloorToInt(timeToDisplay / 60);
    float seconds = Mathf.FloorToInt(timeToDisplay % 60);

    timeText.text = string.Format("{0:00}:{1:00}", minutes, seconds);
}

}

Because you’re not actually calling the Drop() method anywhere?

You either need to put the method into Start(), craft a custom inspector or use something like NaughtyAttributes or OdinInspector to call that method with a button from the inspector or whenever you change that DropdownTimer variable.