Creating signal drop down using vega chart in kibana

Elastic Stack Kibana
1

hi i am trying to create dropdown form kibana fill with some transaction id which coming from index , this is how my vega script look like

{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "width": 500,
  "height": 200,
  "autosize": "none",
  "data": [
    {
      "name": "apiData",
      "url": {
        "%context%": true,
        "%timefield%": "api_request_start_date",
        "index": "*-summary*",
        "body": {
          "aggs": {
            "1": {
              "terms": {
                "field": "fields.transaction_id",
                "size": 10
              }
            }
          }
        },
        "format": {
          "type": "json",
          "property": "aggregations.1.buckets"
        }
      }
    }
  ],
  "signals": [
    {
      "name": "selectedCategory",
      "value": "",
      "bind": {
        "input": "select",
        "options": {
          "signal": "data('apiData').map(d => d.key)"
        },
        "name": "Select Category"
      }
    }
  ],
  "marks": [
    {
      "type": "text",
      "encode": {
        "enter": {
          "x": { "value": 50 },
          "y": { "value": 50 },
          "fontSize": { "value": 20 },
          "fill": { "value": "black" }
        },
        "update": {
          "text": {
            "signal": "selectedCategory === '' ? 'Please select a category' : selectedCategory"
          }
        }
      }
    }
  ]
}

also i have check inspect of kibana and result coming as respected -

{
  "took": 24,
  "timed_out": false,
  "_shards": {
    "total": 36,
    "successful": 36,
    "skipped": 28,
    "failed": 0
  },
  "hits": {
    "total": 198476,
    "max_score": 1,
    "hits": [
      {
        "_index": "apideck-summary-2024-49-0001",
        "_id": "80ff9910-8b52-4505-899f-351bd7d5b61a",
        "_score": 1,
        "_ignored": [
          "processing_end_time",
          "processing_start_time"
        ],
        "_source": {
          "principle_code": "3555",
          "log_id": "80ff9910-8b52-4505-899f-351bd7d5b61a",
          "fields.transaction_id": "80ff9910-8b52-4505-899f-351bd7d5b61a",
          "tenant_code": "7715407",
          "location_code": "",
          "api_request_start_date": "2024-12-02 10:30:17.263",
          "api_request_end_date": "2024-12-02 10:30:17.284",
        
         
        }
      },
    
    ]
  },
  "aggregations": {
    "1": {
      "doc_count_error_upper_bound": 8,
      "sum_other_doc_count": 198466,
      "buckets": [
        {
          "key": "00000ee0-1ffe-4e56-b613-f9c0e3438256",
          "doc_count": 1
        },
        {
          "key": "00005191-8b68-4b6c-a6b6-e64a300a6878",
          "doc_count": 1
        },
        {
          "key": "0001f34f-ca05-4a8a-8933-bf54f49b7827",
          "doc_count": 1
        },
        {
          "key": "00022078-b988-4100-9f27-4a6a52b46f5f",
          "doc_count": 1
        },
        {
          "key": "00024e42-8e19-4b18-9d9e-325e124249cf",
          "doc_count": 1
        },
        {
          "key": "00025017-cca4-418d-b7a9-fe92fbc13baf",
          "doc_count": 1
        },
        {
          "key": "00033317-6b9a-4239-8c93-ac4ebca1a329",
          "doc_count": 1
        },
        {
          "key": "00037bab-fa9d-4cde-ac9f-a950955daa85",
          "doc_count": 1
        },
        {
          "key": "00038aaf-0760-4547-b72c-1182b75ea643",
          "doc_count": 1
        },
        {
          "key": "0003cfde-3819-49ac-8045-3a51aa7da176",
          "doc_count": 1
        }
      ]
    }
  }
}

but still its giving me error

** n.options.forEach is not a function**

any help or suggestion in this .
thanks in advance