I created my own *sty-Package with the basic information which all my documents need like folder structure, colors, etc.

In this file I defined \graphicspath{{./img/}} and in my main file it says "image not found". If I put the command directly into my main file it's working.

*tex

\documentclass{article}
\usepackage{mwe-graphicspath}
\begin{document}
	\includegraphics{lion.png}
\end{document}

*sty

\ProvidesPackage{mwe-graphicspath}[2021/01/13 v1.0 my mwe-graphicspath package]
	\RequirePackage{graphicx}
	\graphicspath{{./img/}}
\endinput