\documentclass{beamer}
\usetheme{Madrid}
\usepackage{tikz}

\setbeamertemplate{footline}{%
    \leavevmode%
    \hbox{%
        \begin{beamercolorbox}[wd=.1\paperwidth,ht=2.25ex,dp=1ex,center]{author in head/foot}%
		\usebeamerfont{author in head/foot}{MOSAID}
        \end{beamercolorbox}%
        \begin{beamercolorbox}[wd=.5\paperwidth,ht=2.25ex,dp=1ex,center]{title in head/foot}%
            \usebeamerfont{title in head/foot}\insertshorttitle\hspace*{0.2em}
	    \hfill \insertframenumber/\inserttotalframenumber\hspace*{0.2em}
        \end{beamercolorbox}%
        \begin{beamercolorbox}[wd=.15\paperwidth,ht=2.25ex,dp=1ex,center]{date in head/foot}%
            \usebeamerfont{date in head/foot}
        \end{beamercolorbox}%
        \begin{beamercolorbox}[wd=.1\paperwidth,ht=2.25ex,dp=1ex,center]{date in head/foot}%
            \usebeamerfont{date in head/foot}\insertdate
        \end{beamercolorbox}%
        \begin{beamercolorbox}[wd=.15\paperwidth,ht=2.25ex,dp=1ex,center]{author in head/foot}%
            \usebeamerfont{date in head/foot}\href{https://www.mosaid.xyz}{www.mosaid.xyz}
        \end{beamercolorbox}%
    }%
    \vskip0pt%
}

\begin{document}

{
\usebackgroundtemplate{
	\tikz\node[overlay,remember picture,opacity=0.9,shift={(3cm,-5cm)}] at (current page.south) {
	\includegraphics[height=0.8\paperheight]{student.png}%width=\paperwidth,
    };
}
\begin{frame}[t]
    \frametitle{How to study for The National Exam}
	Hide your phone for this enitre Month\\
	That's it.
\end{frame}
\usebackgroundtemplate{} % Reset the background template
}

% Normal frame without background
\begin{frame}
    \frametitle{Normal Frame}
    This is a normal frame without background.
\end{frame}

\end{document}