curl --request POST \
  --url https://playground.runa.io/v2/order/estimate \
  --header 'Content-Type: application/json' \
  --header 'X-Api-Key: <api-key>' \
  --data '{
  "payment_method": {
    "type": "ACCOUNT_BALANCE",
    "currency": "USD"
  },
  "items": [
    {
      "products": {
        "type": "MULTIPLE",
        "values": [
          "AMZ-US",
          "AIRBNB-US"
        ]
      },
      "face_value": 10
    }
  ]
}'

{
  "payment_method": {
    "type": "ACCOUNT_BALANCE"
  },
  "items": [
    {
      "products": {
        "type": "MULTIPLE",
        "values": [
          "AMZ-US",
          "AIRBNB-US"
        ]
      },
      "face_value": 10,
      "price": 123,
      "discount_multiplier": 123
    }
  ],
  "currency": "GBP",
  "total_discount": 123,
  "total_price": 123
}