My graphics setting is not working properly!

Hello to everyone. I'm ilyas. The change I made to the game recently is causing problems during the build phase.

the thing is; I recently added a resolution setting to the game. and I worked hard for it. but when I added the "hz" setting to the game in a way that I don't know how, the game started to ignore the resolution setting. Even if the resolution is 1920 by 1080 (16' by 9) my screen looks like a 3:4 ratio. Meanwhile; my window settings are not "resizable". (in-game image)

here is the code i wrote =

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.Audio;
 using UnityEngine.UI;
 
 public class SettingMenu : MonoBehaviour
 {
     public AudioMixer audioMixer;
 
     public TMPro.TMP_Dropdown resolutionDropdown;
 
     Resolution[] resolutions;
 
     private void Start()
     {
       resolutions = Screen.resolutions;
 
       resolutionDropdown.ClearOptions();
 
       List<string> options = new List<string>();
 
       int currentResolutionIndex = 0;
 
       for (int i = 0; i < resolutions.Length; i++)
       {
         string option = resolutions[i].width + " x " + resolutions[i].height //+ " (@" + Screen.currentResolution.refreshRate + " Hz)";
         if(options.Contains(option))
           continue;
         options.Add(option);
         if (resolutions[i].width == Screen.currentResolution.width &&
             resolutions[i].height == Screen.currentResolution.height)
         {
             currentResolutionIndex = i;
         }
       }
 
       resolutionDropdown.AddOptions(options);
       resolutionDropdown.value = currentResolutionIndex;
       resolutionDropdown.RefreshShownValue();
     }
 
     public void SetResolution (int resolutionIndex)
     {
       Resolution resolution = resolutions[resolutionIndex];
       Screen.SetResolution(resolution.width, resolution.height, Screen.fullScreen);
     }
 
     public void SetVolume(float volume)
     {
         audioMixer.SetFloat("volume", volume);
     }
 
     public void SetQuality (int qualityIndex)
     {
       QualitySettings.SetQualityLevel(qualityIndex);
     }
 
     public void SetFullScreen(bool isFullscreen)
     {
      Screen.fullScreen = isFullscreen;
     }
 }

[1]: https://imgur.com/a/SIUwBVN