virtual-university-tour/sources/Assets/Scripting/QuitScript.cs

using UnityEngine;
using UnityEngine.XR.Management;

public class QuitVR : MonoBehaviour
{
    public void Exit()
    {
        var xr = XRGeneralSettings.Instance?
            .Manager?
            .activeLoader;

        if (xr != null)
        {
            XRGeneralSettings.Instance.Manager.StopSubsystems();
            XRGeneralSettings.Instance.Manager.DeinitializeLoader();
        }

        Application.Quit();
    }
}