curl --request GET \
  --url https://open.bigmodel.cn/api/llm-application/open/v2/application/{app_id}/variables \
  --header 'Authorization: Bearer <token>'

{
  "data": [
    {
      "id": "<string>",
      "name": "<string>",
      "type": "<string>",
      "tips": "<string>",
      "allowed_values": [
        "<string>"
      ],
      "input_template": {
        "options": [
          "<any>"
        ]
      }
    }
  ],
  "code": 123,
  "message": "<string>",
  "timestamp": 123
}