curl -X DELETE https://api.bland.ai/v1/knowledge/kb_01H8X9QK5R2N7P3M6Z8W4Y1V5T \
  -H "authorization: YOUR_API_KEY"

{
  "data": {
    "success": true,
    "message": "Knowledge base successfully deleted",
    "knowledge_base_id": "kb_01H8X9QK5R2N7P3M6Z8W4Y1V5T"
  },
  "errors": null
}

{
  "data": null,
  "errors": [
    {
      "error": "KB_ERROR",
      "message": "KB not found or access denied"
    }
  ]
}