How to disable field from being generated

Hi, is it possible to disable field from being generated, like in this schema I would like to keep ‘headers’ static as is, but ‘data’ to be generated in 500 rows.

{
   "headers": {
      "assetId": {
         "title": "id",
         "isVisible": false
      },
      "customerIdentifier": {
         "title": "name",
         "isVisible": true
      },
      "riskScore": {
         "title": "risk score",
         "isVisible": true
      },
      "serialNumber": {
         "title": "serial number",
         "isVisible": true
      }
   },
   "data": [
      {
         "assetId": 1,
         "customerIdentifier": "Pannier",
         "riskScore": "84",
         "serialNumber": "15-581-8579"
      }
   ]
}