\documentclass[12pt,twoside]{article} 
\usepackage[utf8]{inputenc}
\usepackage{amsmath,amsfonts,amssymb,verbatim,graphicx,geometry}
\geometry{a4paper}
\thispagestyle{empty}

\begin{document}
\emph{\hspace*{-0.6cm}\textbf{Journ\'ees de Statistique Math\'ematique et Data Science (JSMDS 2021)} \\ Hammamet, Tunisie, 25-28 novembre 2021}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%% DO NOT ALTER ABOVE  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\begin{center}
\Large{\textbf{Title of communication}}
\vspace{.5cm}

Name SURNAME author 1\footnote{Institution of author 1}, 
Name SURNAME author 2\footnote{Institution of author 2} % add as many authors as necessary
\end{center}
\vspace{0.5cm}

\hrule height 0.3ex

\vspace{0.3cm}

\noindent \textbf{Abstract:}
\vspace{.5cm}

\noindent Write the abstract here (15 lines maximum).
\vspace{.5cm}

\noindent \textbf{Keyword :}  keyword\_1 ; keyword\_2 ; keyword\_3; keyword\_4
\vspace{0.5cm}

\hrule height 0.3ex

\section*{References}

\begin{enumerate}
\item Author 1, author 2, author 3. Title of paper/book. Journal name, num., pp., year.
\item Author 1, author 2, author 3. Title of paper/book. Journal name, num., pp., year.
\item Author 1, author 2, author 3. Title of paper/book. Journal name, num., pp., year.
\item Author 1, author 2, author 3. Title of paper/book. Journal name, num., pp., year.
\end{enumerate}

\end{document}