Unlike the Android, where permissions can be queried from a single access point using the Runtime Permissions SDK. On iOS, permissions are bound to each module, and modules can have different permissions API, and provide a different scope of information. You can get more information about with iOS Native Permissions guide

To simplify cross-platform permissions management, and also provide an ability to test the flow inside an Editor, Ultimate Mobile plugin contains the Unified Permissions API.

Use UM_Permissions as the main entry point for the Permissions Services APIs. The UM_Permissions contains UM_IPermission clients for:

  • Contacts
  • Notifications
  • Camera
  • Photos

The UM_IPermission client interface is pretty simple to use, see the declaration below:

namespace SA.CrossPlatform.App
    public interface UM_IPermission
        /// <summary>
        /// Requests the user’s permission, if needed.
        /// After the user grants permission, the system remembers the choice for future use in your app, 
        /// but the user can change this choice at any time using the Settings app.
        /// If user denied your app access, this choice will also be remembered and attempt to call
        /// RequestAccess again will not display any permission prompt and failed result will be fired immediately. 
        /// </summary>
        /// <param name="callback">Callback fired upon determining your app’s authorization to access requested permission.</param>
        void RequestAccess(Action<AuthorizationStatus> callback);

 And of course, there is an example of how you can request Camera permission The code would look the same for any other permission client. 

Note: Plese make sure you enable iOS module correspondent to permissions API you going to use.  See the description inside the UM_Permissions or check modules & permissions dependency with the iOS Native Permissions guide

using SA.CrossPlatform.App;

UM_Permissions.Camera.RequestAccess((status) =>
    if (status == AuthorizationStatus.Granted)
        Debug.Log("Camera Access Granted");
        Debug.Log("Camera Access Denied");