services_core/app/Http/Resources/Notification/NotificationDeliveryResource.php

<?php

namespace App\Http\Resources\Notification;

use Illuminate\Http\Request;
use Illuminate\Http\Resources\Json\JsonResource;

class NotificationDeliveryResource extends JsonResource
{
    public function toArray(Request $request): array
    {
        $destination = (string) $this->destination;
        $masked = strlen($destination) > 6
            ? substr($destination, 0, 3).str_repeat('*', max(3, strlen($destination) - 6)).substr($destination, -3)
            : str_repeat('*', strlen($destination));

        return [
            ...parent::toArray($request),
            'destination' => $masked,
            'message' => $this->whenLoaded('message'),
            'channel_config' => $this->whenLoaded('channelConfig'),
        ];
    }
}