curl --request POST \
  --url https://api.sand.getivy.de/api/service/customer/retrieve \
  --header 'Content-Type: application/json' \
  --header 'X-Ivy-Api-Key: <api-key>' \
  --data '{
  "id": "<string>"
}'

{
  "id": "<string>",
  "emailAddress": "<string>",
  "bankAccounts": [
    {
      "last4digits": "<string>",
      "bank": {
        "id": "<string>",
        "logo": "<string>",
        "name": "<string>"
      }
    }
  ]
}