A script for managing permissions across Apple Vision Pro, Meta Quest and Android XR. It references world space UI element to let the user know about missing or denied permissions.

XRPermissions.cs

using UnityEngine;
using UnityEngine.XR.ARFoundation;
using System.Collections.Generic;
using TMPro;
using UnityEngine.Android;
#if UNITY_VISIONOS
using UnityEngine.XR.VisionOS;
#endif

public class XRPermissions : MonoBehaviour
{

    // meta quest
    const string k_MetaScenePermissionId = "com.oculus.permission.USE_SCENE";
    const string k_MetaHandPermissionId = "com.oculus.permission.HAND_TRACKING";
    
    // android xr
    const string k_AndroidXRSceneMinPermissionId = "android.permission.SCENE_UNDERSTANDING_COARSE";
    const string k_AndroidXRSceneMaxPermissionId = "android.permission.SCENE_UNDERSTANDING_FINE";
    const string k_AndroidXRHandPermissionId = "android.permission.HAND_TRACKING";
   
    [SerializeField]
    ARPlaneManager m_PlaneManager;
    
    [SerializeField]
    HandTrackingManager m_HandManager;

    [SerializeField]
    GameObject m_DeniedPermissionsPopup;
    
    [SerializeField]
    TMP_Text m_DeniedPermissionsText;
    
#if UNITY_VISIONOS
        void OnEnable()
        {
            VisionOS.AuthorizationChanged += OnAuthorizationChanged;
        }

        void OnDisable()
        {
            VisionOS.AuthorizationChanged -= OnAuthorizationChanged;
        }

        void UpdateAuthorizationText()
        {
            var type = VisionOSAuthorizationType.HandTracking;
            var status = VisionOS.QueryAuthorizationStatus(type);
            OnAuthorizationChanged(new VisionOSAuthorizationEventArgs { type = type, status = status });

            type = VisionOSAuthorizationType.WorldSensing;
            status = VisionOS.QueryAuthorizationStatus(type);
            OnAuthorizationChanged(new VisionOSAuthorizationEventArgs { type = type, status = status });
        }

        void OnAuthorizationChanged(VisionOSAuthorizationEventArgs args)
        {
            switch (args.type)
            {
                case VisionOSAuthorizationType.HandTracking:
                    if (args.status == VisionOSAuthorizationStatus.Denied)
                    {
                        m_DeniedPermissionsText.text += "Hand permission \n";
                    } 
                    break;
                case VisionOSAuthorizationType.WorldSensing:
                    if (args.status == VisionOSAuthorizationStatus.Denied)
                    {
                       m_DeniedPermissionsText.text += "Scene permission \n"; 
                    }
                    break;
                // We do not support CameraAccess yet so ignore it
            }
            
            m_DeniedPermissionsPopup.SetActive(true);
        }
#endif

    void Start()
    {
        var permissions = new List<string>();
        m_DeniedPermissionsText.text = "";
       
#if UNITY_META_QUEST
        // add permissions that have not been granted by the user
        if (!Permission.HasUserAuthorizedPermission(k_MetaScenePermissionId))
        {
            permissions.Add(k_MetaScenePermissionId);
        }
        else
        {
            // enable the AR Plane Manager component if permission is already granted
            m_PlaneManager.enabled = true;
        }

        if (!Permission.HasUserAuthorizedPermission(k_MetaHandPermissionId))
        {
            permissions.Add(k_MetaHandPermissionId);
        }
        else
        {
            m_HandManager.enabled = true;
        }
#elif UNITY_ANDROID_XR
        // add permissions that have not been granted by the user
        if(!Permission.HasUserAuthorizedPermission(k_AndroidXRSceneMinPermissionId))
        {
            permissions.Add(k_AndroidXRSceneMinPermissionId);
        }
        else
        {
            m_PlaneManager.enabled = true;
        }
        
        if(!Permission.HasUserAuthorizedPermission(k_AndroidXRHandPermissionId))
        {
            permissions.Add(k_AndroidXRHandPermissionId);
        }
        else
        {
            m_HandManager.enabled = true;
        }
#elif UNITY_VISIONOS
        UpdateAuthorizationText();
#endif
        // setup callbacks to be called depending on whether permission is granted
        var callbacks = new PermissionCallbacks();
        callbacks.PermissionDenied += OnPermissionDenied;
        callbacks.PermissionGranted += OnPermissionGranted;

        Permission.RequestUserPermissions(permissions.ToArray(), callbacks);
    }
    void OnPermissionDenied(string permission)
    {
        // handle denied permission
        Debug.LogError($"Permission {permission} was denied by the user");
        
        // show a popup to inform the user that the permission is required
        if(permission == k_MetaScenePermissionId || permission == k_AndroidXRSceneMinPermissionId)
        {
            m_DeniedPermissionsText.text += "Scene permission \n";
        }
        
        if(permission == k_MetaHandPermissionId || permission == k_AndroidXRHandPermissionId)
        {
            m_DeniedPermissionsText.text += "Hand permission \n";
        }

        m_DeniedPermissionsPopup.SetActive(true);
    }

    void OnPermissionGranted(string permission)
    {
        // enable the corresponding AR Manager component after required permission is granted
        if (permission == k_MetaScenePermissionId || permission == k_AndroidXRSceneMinPermissionId)
        {
            m_PlaneManager.enabled = true;
        }
        
        if(permission == k_MetaHandPermissionId || permission == k_AndroidXRHandPermissionId)
        {
            m_HandManager.enabled = true;
        }
    }
}