When I was studying in the United States, I often saw all kinds of colorful gift cards near the cashier in convenience stores, which were very conspicuous. Common ones are gift cards issued by iTunes, eBay, Amazon, Walmart and other large companies, and of course there are credit cards. For details. I have bought some gift cards with a face value of $25 (Visa, MasterCard, American Express) and they are relatively convenient to use. This kind of gift card needs to be activated online before use. The activation address can be found on the gift card packaging. When activating, you need to enter your name, zip code, phone number, and billing address. When you consume online, you will generally verify that the information is consistent. If you fill in the wrong information, the transaction will be rejected.