GET
    /custom-field-purchases/{id}.json
  
  curl \
 --request GET 'http://api.example.com/v1/custom-field-purchases/{id}.json' \
 --header "Authorization: Bearer $ACCESS_TOKEN"
    
        Response examples (200)
  
  {
  "createdAt": "2025-05-04T09:42:00Z",
  "customFieldId": 42,
  "id": 42,
  "object": {},
  "purchaseId": 42,
  "updatedAt": "2025-05-04T09:42:00Z",
  "value": "string",
  "values": [
    "string"
  ]
}