update api register

app/Models/SystemNotificationCampaign.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+
+class SystemNotificationCampaign extends Model
+{
+    protected $guarded = ['id'];
+
+    protected function casts(): array
+    {
+        return ['audience' => 'array', 'completed_at' => 'datetime'];
+    }
+
+    public function tenant()
+    {
+        return $this->belongsTo(Tenant::class);
+    }
+
+    public function creator()
+    {
+        return $this->belongsTo(User::class, 'created_by');
+    }
+
+    public function notifications()
+    {
+        return $this->hasMany(UserNotification::class);
+    }
+}