curl "https://app.talkover.ai/api/v1/auto-topup/payment-methods" \
  -H "Authorization: Bearer talq_your_environment_token_here"

{
  "success": true,
  "data": [
    {
      "id": "pm_uuid_1",
      "type": "card",
      "card": {
        "brand": "visa",
        "last4": "4242",
        "exp_month": 12,
        "exp_year": 2027
      },
      "is_default": true,
      "created_at": "2024-01-01T10:00:00Z"
    },
    {
      "id": "pm_uuid_2",
      "type": "card",
      "card": {
        "brand": "mastercard",
        "last4": "5555",
        "exp_month": 8,
        "exp_year": 2026
      },
      "is_default": false,
      "created_at": "2024-01-05T14:00:00Z"
    }
  ]
}