Use makeindex with pandoc while creating a PDF from a Markdown file - pdf

Question

I have got a markdown file and like to convert it to pdf. I need an index. For this I found makeindx
I am using this command for creating a pdf from a markdown file:
pandoc "test.md" \
--from markdown --to latex \
--toc \
--toc-depth=1 \
--include-in-header index.tex \
--include-in-header chapter_break.tex \
--include-in-header inline_code.tex \
--include-in-header bullet_style.tex \
--include-in-header pdf_properties.tex \
--highlight-style pygments.theme \
-V toc-title='Inhaltsverzeichnis' \
-V title='Mein Titel' \
-V author='Ich' \
-V book=true \
-V date="24. Mai 2021" \
-V classoption='oneside' \
--template ./eisvogel.latex \
--listings \
-o "test.pdf"
The template Eisvogel I found on github. I asked the question in an issue here, too.
The file index.tex has this content:
\usepackage{makeidx}
\makeindex
In my document I use
Installation\index{Installation}
and at the end
\printindex
Unfortunately, no index is printed.
Am I doing something wrong?
Edit I found a temporarily solution:
First I create a *.latex.
pandoc JoomlaEnPDF.en.md \
-o 1.en.tex \
--from markdown \
--template ./eisvogel.latex \
--listings \
--toc \
--toc-depth=1 \
-V toc-title="Content" \
--top-level-division="part" \
--number-sections \
Then I run the commands manually.
pdflatex 1.en.tex
pdflatex 1.en.tex
makeindex 1.en.idx
cat ./1.en.ind >> JoomlaEnPDF.en.md
Then I create the pdf
pandoc JoomlaEnPDF.en.md \
-o 1.en.pdf \
--from markdown \
--template ./eisvogel.latex \
--listings \
--toc \
--toc-depth=1 \
-V toc-title="Table of Contents" \
--top-level-division="part" \
--number-sections \