\documentclass[aspectratio=169]{beamer}
\usepackage{mum-theme-beamer/mum-theme}

\title{My Title}
\subtitle{My Subtitle}
\date{03.11.2023}
\author[Short Author Name]{Long Author Name}
\institute[TUHH]{Hamburg University of Technology}

\begin{document}
\begin{frame}
	\titlepage
\end{frame}
\begin{frame}
	\frametitle{First Slide Title}
    Content of First Slide
\end{frame}
\end{document}