|string> */ public function rules(): array { return [ 'customer_id' => 'required', 'payment_method' => 'required', 'status' => 'required', 'product.*.product_id' => 'required|numeric|not__in:0', 'product.*.os_id' => 'nullable|integer', 'product.*.billing' => 'required|not__in:0', 'product.*.quantity' => 'required|min:1', ]; } }