OVRSpatialAnchor.Share() fails.

The problem has solved. Thank you loic-all!

https://github.com/oculus-samples/Unity-SharedSpatialAnchors/issues/4

FYI, this is the code that succeeds in Share().

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using Oculus.Platform;

public class SpatialAnchorSender : MonoBehaviour
{
    void Start()
    {
        StartCoroutine(Share());
    }

    IEnumerator Share()
    {
        var anchor = gameObject.AddComponent<OVRSpatialAnchor>();
        yield return new WaitUntil(() => anchor.Created);
        var anchors = new HashSet<OVRSpatialAnchor> { anchor };

        Core.Initialize();

        Users.GetLoggedInUser().OnComplete(message =>
        {
            var user = new OVRSpaceUser(message.GetUser().ID);
            var users = new HashSet<OVRSpaceUser> { user };
            var saveOptions = new OVRSpatialAnchor.SaveOptions { Storage = OVRSpace.StorageLocation.Cloud };

            OVRSpatialAnchor.Save(anchors, saveOptions, (collection, result) =>
            {
                if (result is not OVRSpatialAnchor.OperationResult.Success)
                {
                    Debug.LogError(result);
                    return;
                }

                OVRSpatialAnchor.Share(collection, users, (collection, result) =>
                {
                    if (result is OVRSpatialAnchor.OperationResult.Success)
                    {
                        Debug.Log("Success sharing anchor.");
                    }
                    else
                    {
                        Debug.LogError(result);
                    }
                });
            });
        });
    }
}