Adding a table of contents in an r notebook

Question

There doesn't seem to be a problem when I add a table of contents to an r markdown file but nothing happens when I add this to an r notebook:

output: 
   html_document:
   html_notebook:
      toc: true
      depth: 3
      theme: united

Is it possible to add a table of contents to an R notebook or do I have to make this into a markdown file too?

Answer 1

I had to format it like this in the end:

output: 
  html_notebook:
    theme: united
    toc: yes

Answer 2

Try formatting like this:

title: "Title"
output:
  html_notebook:
    theme: united
    toc: yes