BookStack/dev/api/requests/chapters-update.json

{
  "book_id": 1,
  "name": "My fantastic updated chapter",
  "description_html": "<p>This is an <strong>updated chapter</strong> that I've altered via the API</p>",
  "priority": 16,
  "tags": [
    {"name": "Category", "value": "Kinda Good Content"},
    {"name": "Rating", "value": "Medium"}
  ]
}