ltxtest.tex

\documentclass{beamer}
\usetheme{metropolis}
\usepackage[backend=biber, style=chem-angew, safeinputenc]{biblatex}
% \renewcommand\multicitedelim{\addsemicolon\space}

\begin{filecontents}{\jobname.bib}
  @misc{Book1,
  author = {Author, A.},
  year = {2001},
  title = {Alpha},
  }
  @misc{Book2,
  author = {Buthor, B.},
  year = {2002},
  title = {Bravo},
  }
\end{filecontents}

\addbibresource{\jobname.bib}

\begin{document}
\begin{frame}{Test}

% Check.\footfullcite{Book1}
Check.\footfullcite{Book1}\footfullcite{Book2}

\end{frame}
\end{document}