curl --request GET \
  --url https://{subdomain}.nudj.cx/api/v2/admin/variables \
  --header 'x-api-token: <api-key>'

{
  "totalCount": 123,
  "edges": [
    {
      "id": "<string>",
      "organisationId": "<string>",
      "type": "form-short-text",
      "name": "<string>",
      "label": "<string>",
      "placeholder": "<string>",
      "useDefaultProfileValue": true,
      "availableInQuestionBank": true,
      "maxValueOccurrences": 2,
      "isSingleOutputPerUser": true,
      "isImmutable": true,
      "prerequisiteVariableConfigIds": [
        "<string>"
      ],
      "options": [
        {
          "key": "<string>",
          "value": "<string>"
        }
      ],
      "validationRegex": "<string>",
      "validationEndpointConfig": {
        "url": "<string>",
        "method": "<string>",
        "headers": {}
      },
      "createdAt": "<string>",
      "createdBy": "<string>",
      "updatedAt": "<string>",
      "updatedBy": "<string>"
    }
  ]
}