Hey there! I totally get how frustrating it is to spend hours hunting for a PayPal setup that fits your Argentine company's specific needs—let's break this down clearly, addressing all your requirements one by one.

First off, let's clarify that note you found about the Payments REST API not being used for credit card payments: that's partially accurate. You shouldn't manually collect and process credit card details via the REST API (that would require heavy PCI compliance work), but you can absolutely use PayPal's hosted payment components with the REST API to enable guest credit card payments safely.

1. Core Solution for Argentine Businesses: PayPal Smart Payment Buttons #

The PayPal Smart Payment Buttons are your best bet here. They're fully supported for Argentine merchant accounts, and they natively offer Guest Checkout—meaning users don't need a PayPal account to pay with their credit card.

Quick Integration Steps: #

• First, log into your PayPal Developer Dashboard (linked to your Argentine business account) and create an app to get your CLIENT_ID and SECRET keys.
• Embed the button code on your frontend, making sure to enable guest checkout explicitly (some regions hide it by default):

  paypal.Buttons({
    createOrder: (data, actions) => {
      // Pull order details from your backend to avoid frontend tampering
      return actions.order.create({
        purchase_units: [{
          amount: {
            value: '1500.00', // Replace with your ARS amount
            currency_code: 'ARS'
          }
        }]
      });
    },
    onApprove: (data, actions) => {
      return actions.order.capture().then(details => {
        // Handle successful payment (but always verify via backend!)
        console.log(`Payment approved for ${details.payer.name.given_name}`);
      });
    },
    // Force-enable guest checkout option
    enableStandardCardFields: true
  }).render('#paypal-button-container');
  

• Double-check that your PayPal business account has ARS (Argentine Peso) enabled as a supported currency—you can set this up in your account's payment settings.

2. Implementing Tamper-Proof Security #

To keep your payment flow secure and tamper-proof, you need layers of protection on both frontend and backend:

• Frontend Safeguards:
  • Never hardcode sensitive values like payment amounts in the frontend. Instead, fetch order details (amount, item IDs, etc.) from your backend API right before creating the PayPal order.
  • Let PayPal's hosted button handle all payment entry—this prevents any malicious manipulation of card details or payment parameters on your end.
• Backend Verification (Critical!):
  • Don't trust frontend payment success messages alone. After the user completes payment, call PayPal's REST API endpoint GET /v2/checkout/orders/{order_id} from your backend to confirm the order's actual status, amount, and payer details.
  • Set up PayPal Webhooks and subscribe to the CHECKOUT.ORDER.COMPLETED event. This way, PayPal will send a direct, verified notification to your backend when a payment is finalized—no reliance on frontend signals.
  • Enable webhook signature verification in your PayPal dashboard to ensure incoming notifications are actually from PayPal, not fake requests.

3. Argentina-Specific Tips #

• Make sure your PayPal business account is registered in Argentina and fully verified (you'll need to submit business docs like yourCUIT/CUIL, company registration, etc.).
• For compliance in Argentina, you may need to collect the payer's CUIT/CUIL. You can include this in the order creation request:

  purchase_units: [{
    amount: { value: '1500.00', currency_code: 'ARS' },
    payer: {
      tax_info: {
        tax_id: '123-4567890-1',
        tax_id_type: 'CUIT'
      }
    }
  }]
  

• If the guest checkout option isn't showing up, head to your PayPal business dashboard's Payment Settings and ensure "Allow guests to check out without a PayPal account" is enabled.

内容的提问来源于stack exchange，提问作者Adrián E