\documentclass{beamer}
\usepackage[backend=biber]{biblatex}
\begin{filecontents*}[overwrite]{mylist.bib}
@book{test,
author = {Coucou},
title = {lalalala}
}
\end{filecontents*}
\addbibresource{mylist.bib}
\usepackage{tcolorbox}
\begin{document}
\begin{frame}
\frametitle{Test}
\begin{tcolorbox}
test\footnote[frame]{\fullcite{test}}
\end{tcolorbox}
\end{frame}
\end{document}\end{document}
![alt text][1]
[1]: https://texnique.fr/osqa/upfiles/document_VwsuVw2.png
