Help locals 🥹

Hi ! I’m currently studying Mandarin in Taiwan. I buy food and other necessities in supermarkets and convenience stores. I have a hard time responding to the cashiers if I need the printed QR code (for lottery). What sentence do they usually say?

Because I’m familiar with the word 袋子 when they ask if I need the bag and I can respond to them easily.

I appreciate you for responding and thank you for your time !