すみません、〇〇ペイは使えますか？ — Excuse me, can I use 〇〇 Pay? (Convenience · Store, Formal — to staff, JLPT N4)

Gesture & etiquette

Hold up your phone or card if it's a mobile payment. (Replace 〇〇 with the actual payment service name, e.g., 'Alipay', 'WeChat Pay', 'Google Pay').

Be prepared to pay with cash or a different method if your preferred one isn't accepted. Don't argue.