ldc-legaulois/app/Models/Notifications.php

<?php

namespace App\Models;

use App\Enums\NotificationType;
use Illuminate\Database\Eloquent\Model;

class Notifications extends Model
{

    protected $enumCasts = [
        'type' => NotificationType::class
    ];

    protected $fillable = [
        'type',
        'content',
        'customer_id'
    ];

    /**
     * Polymorphic relation : Get the parent model
     */
    public function notifiable()
    {
        return $this->morphTo();
    }
}