Simple TeX template to generate compliant applications to get my g'damn money back!

__auslagenerstattung.tex

\documentclass{article}
\usepackage{graphicx}
\usepackage{pdfpages}% https://ftp.rrze.uni-erlangen.de/ctan/macros/latex/contrib/pdfpages/pdfpages.pdf
\usepackage[a4paper, margin=5mm]{geometry}
%
% ============ Input Files ==================
\newcommand{\bill}{rechnung.png}
\newcommand{\pdf}{ausgefuellter_und_signierter_antrag.pdf}
% ===========================================
%
\begin{document}
\thispagestyle{empty}
\includepdf[pages=-]{\pdf}
\newpage
\thispagestyle{empty}
\begin{figure}[htbp]
    \centering
    \includegraphics[width=\dimexpr\textwidth-1cm\relax, height=\dimexpr\textheight-1cm\relax, keepaspectratio]{\bill}
\end{figure}
\end{document}