Azure policy block all vm extensions

blockallextensions.json

{
  "properties": {
    "displayName": "Block all azure vm extensions policy",
    "policyType": "Custom",
    "mode": "All",
    "metadata": {
      "version": "2.0.0",
      "createdBy": "73175a57-a138-4125-8bf9-8373cff050bf",
      "createdOn": "2023-11-09T19:12:54.3579633Z",
      "updatedBy": null,
      "updatedOn": null
    },
    "parameters": {
      "effect": {
        "type": "String",
        "metadata": {
          "displayName": "Effect",
          "description": "Deny, Audit or Disabled the execution of the Policy"
        },
        "allowedValues": [
          "Deny",
          "Audit",
          "Disabled"
        ],
        "defaultValue": "Audit"
      }
    },
    "policyRule": {
      "if": {
        "allOf": [
          {
            "field": "type",
            "equals": "Microsoft.Compute/virtualMachines/extensions"
          }
        ]
      },
      "then": {
        "effect": "[parameters('effect')]"
      }
    }
  },
  "id": "/providers/Microsoft.Management/managementGroups/1a82558d-66e0-48b0-b370-72df4caf1852/providers/Microsoft.Authorization/policyDefinitions/68632339-d04c-467b-8404-30719d9347ee",
  "type": "Microsoft.Authorization/policyDefinitions",
  "name": "68632339-d04c-467b-8404-30719d9347ee",
  "systemData": {
    "createdBy": "test@example.com",
    "createdByType": "User",
    "createdAt": "2023-11-09T19:12:54.3207244Z",
    "lastModifiedBy": "test@example.com",
    "lastModifiedByType": "User",
    "lastModifiedAt": "2023-11-09T19:12:54.3207244Z"
  }
}