How do you use Apple Wallet Apple Pay to pay for things at stores with your iPhone?

I have downloaded Apple Wallet, and was able to add my debit card to this app. However, I'm confused about how to use it in stores or restaurants. I'm in Japan now, and I'm not even sure you can use it to pay for things, but I can try. Has anyone ever used this to pay for things abroad? Please tell me how it works. Thanks.

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1 mo
By the way, I have an iPhone 14 with an E-sim card, not a regular SIM card in it. Sim is not an actual physical chip or card.
How do you use Apple Wallet Apple Pay to pay for things at stores with your iPhone?
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