Section outlines in beamer Rmarkdown?

Question

How can I have the outline of a beamer presentation appear before each section in Rmarkdown, like this code for regular beamer?

Answer 1

Put this code in header.tex:

\AtBeginSection[]
{
 \begin{frame}<beamer>
 \frametitle{Plan}
 \tableofcontents[currentsection]
 \end{frame}
}

And compile with:

---
output: 
  beamer_presentation:
    includes:
      in_header: header.tex
---