FromChainPayment Gateway

// Default: USDT BEP20 (Binance Smart Chain)
const response = await fetch('https://api.fromchain.plus/v1/invoices', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer gw_live_your_api_key_here',
    'Content-Type': 'application/json',
    'Idempotency-Key': 'order_123_payment'
  },
  body: JSON.stringify({
    amount: '100.00',          // Only required field!
    externalId: 'order_123',
    description: 'Payment for Order #123',
    metadata: {
      customerId: 'user_456',
      orderId: 'order_123'
    }
  })
});

const invoice = await response.json();
console.log(invoice);
// {
//   "id": "inv_abc123",
//   "chain": "BSC",
//   "token": "USDT",
//   "depositAddress": "0x1234567890...",
//   "amountExpected": "100.00",
//   "status": "PENDING"
// }