I'm trying to set a default value to a user picker using the SendingContentNotification so the picker gets automatically populated when the user creates the content, but the picker doesn't show the user as expected. The code I'm using:

if(notification.Content.ContentTypeAlias != Post.ModelTypeAlias)
            return;

        foreach (var variant in notification.Content.Variants)
        {
            var postAuthor = variant.Tabs.SelectMany(f => f.Properties)
                .FirstOrDefault(f => f.Alias.InvariantEquals("author"));
            
            if(variant.State != ContentSavedState.NotCreated)
                return;

            var loggedInUser = _backOfficeSecurityAccessor?.BackOfficeSecurity?.CurrentUser;
            if (loggedInUser == null) return;
            
            if (postAuthor != null)
            {
                postAuthor.Value = loggedInUser.Id;
            }
        }

If I do this with the ContentSavingNotification it works but I prefer to set the default so the Editor know that their user will be the author unless he/she change the value.

User pick only accepts an ID ?

I've tryed but GetUDI() in user gives an error saying "not supported in this entity type". Aside from that, I've checked and in this case, is the ID that is saved in the database as a value for my property I don't know if the problem is specific just to the IUser type