i would like to build a png-image below the sidebar on the right in a quarto-book:

I have tried to find a solution with the help of ChatGPT. Unfortunately not successful. So I don’t have a solution. But here is my code:

index.qmd:

# Preface {.unnumbered}

This is a Quarto book.

To learn more about Quarto books visit <https://quarto.org/docs/books>.

_quarto.yml:

project:
  type: book

book:
  title: "q_book_exampl"
  author: "Norah Jones"
  date: "2.7.2024"
  chapters:
    - index.qmd 
format:
  html:
    theme: cosmo 

Here is the test image: