Create transaction session

curl --request POST \
  --url https://ebt-sandbox.bennyapi.com/v1/transaction \
  --header 'Content-Type: application/json' \
  --header 'api-key: <api-key>' \
  --data '{
  "externalCustomerId": "cust_123",
  "externalTransactionId": "txn_ext_456",
  "items": [
    {
      "id": "item_1",
      "description": "Apples",
      "quantity": 2.5,
      "unit": "LBS",
      "price": 199,
      "snapEligible": true,
      "taxRate": 0,
      "photoUrl": "https://cdn.example.com/items/apples.jpg"
    },
    {
      "id": "item_2",
      "description": "Whole Wheat Bread",
      "quantity": 1,
      "unit": "COUNT",
      "price": 350,
      "snapEligible": true,
      "taxRate": 0
    },
    {
      "id": "item_3",
      "description": "Shampoo",
      "quantity": 1,
      "unit": "COUNT",
      "price": 899,
      "snapEligible": false,
      "taxRate": 0.08
    }
  ]
}'

{
  "sessionUrl": "https://checkout.bennyapi.com/session?transactionId=txn_a1b2c3d4e5f6g7h8"
}