update or create relation laravel code example

Example: laravel update or create wioth hasmany relation

class Item extends Model
{
    protected $fillable = ['menu_id', 'parent_id', 'title', 'order', 'resource_link', 'html_class', 'is_blank'];

    public function translations()
    {
        return $this->hasMany(MenuItemTranslation::class, 'menu_item_id');
    }
}