Add or remove "References" in TOC at end of each chapter in bookdown::gitbook

Question

I am compiling a bookdown::gitbook and want to include a "References" header for each chapter in the TOC.

Currently, I have included a level 2 header titled "References" at the end of each chapter which appears in the TOC, however in-text there are two "References" headers: my level 2 header and a (level 3?) header which gets added once you build the book.

I want a (linked) References header in the TOC, and I only want one header in the text. I assume the options include:

1. Add the automatically included (level 3?) header to the TOC, or
2. Remove the level 3 header altogether, and just use my own level 2 header.

Is there a way to achieve either of these 2 points? I think I would prefer a solution to option 2, so that then the name and formatting of the header may be changed (font, colour, size etc) in line with the rest of the level 2 headers in the book.

This is a screenshot of my book. The header underlined in red is the level 2 header I have included, and the one circled in cyan is the level 3(?) one which is automatically added (as you can see it is slightly smaller than the one underlined in red).

I have recreated the issue with the demo book from here https://bookdown.org/yihui/bookdown/get-started.html, and have tried the following:

---

To include the level 3 header in the TOC

https://stackoverflow.com/a/69545034/13478749

header_includes:
- \usepackage[nottoc,numbib]{tocbibind}

This had no effect.

---

To include the level 3 header in the TOC

https://stackoverflow.com/a/51575615/13478749

bookdown::render_book("index.Rmd", "bookdown::gitbook", output_options=list(toc_bib = TRUE))

This had no effect.

---

So I thought I could at least try and change the name of the automatic level 3 header using this in the YAML, but it resulted in an error.

https://stackoverflow.com/a/64276396/13478749

---
reference-section-title: Referencias
---

Error in vapply(idx2, character(1), FUN = function(i) head(nms[idx > i],  : 
  values must be length 1,
 but FUN(X[[8]]) result is length 0
Calls: <Anonymous> ... <Anonymous> -> <Anonymous> -> split_chapters -> vapply
Execution halted

Exited with status 1.

But if I include an empty string as the new title, there is no error, but the level 3 "References" header remains (I assume R ignores reference-section-title because it is empty).

---
reference-section-title: ' '
---

---

And this answer https://stackoverflow.com/a/51494840/13478749 (and the cited bookdown documentation https://bookdown.org/yihui/bookdown/citations.html) refers to the name of the final chapter in the book, which you add in yourself as a level 1 header anyway, rather than the automatically-added level 3 header at the end of each chapter.

if (knitr::is_html_output()) '# Literatur {-}'

---