merge_pdf.tex

\documentclass{article}% or something else
%\usepackage{pdfpages}
\usepackage{graphicx}
\usepackage[export]{adjustbox}
\begin{document}


%\includepdf[pages={1-2}]{Eandisform_copy}
%\includepdf{SCAN0145.JPG}



%\includepdf{/home/stijn/Downloads/IMG_20210906_222257846.jpg}
%\includepdf{/home/stijn/Downloads/IMG_20210906_222231331.jpg}

%\includegraphics[width=\textwidth,height=\textheight,keepaspectratio]{/home/stijn/Downloads/IMG_20210906_222257846.jpg}
%\includegraphics[width=\textwidth,height=\textheight,keepaspectratio]{/home/stijn/Downloads/IMG_20210906_222231331.jpg}

%\begin{figure}[p]
%\includegraphics[max size={\textwidth}{\textheight}]{/home/stijn/Downloads/IMG_20210906_222257846.jpg}
%\end{figure}

\begin{figure}[p]
\includegraphics[max size={\textwidth}{\textheight}]{/home/stijn/Downloads/IMG_20210906_222231331.jpg}
\end{figure}


\end{document}