exchange/app/Models/Document.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use Backpack\CRUD\app\Models\Traits\SpatieTranslatable\HasTranslations;

class Document extends Model
{
    use \Backpack\CRUD\app\Models\Traits\CrudTrait;
    use HasFactory;
    use HasTranslations;

    protected $guarded = [''];
    public $translatable = ['title', 'file'];

    public static function boot()
    {
        parent::boot();
        static::deleting(function($obj) {
            \Storage::disk('uploads')->delete($obj->image);
        });
    }

    public function setFileAttribute($value)
    {
        $attribute_name = "file";
        $disk = config('backpack.base.root_disk_name');
        $destination_path = "public/uploads/documents";

        $this->uploadFileToDisk($value, $attribute_name, $disk, $destination_path, $fileName = null);

        return $this->attributes[$attribute_name]; // uncomment if this is a translatable field

    }

    public function documentCategory()
    {
        return $this->belongsTo(DocumentCategory::class);
    }

}