overleaf/services/web/app/templates/project_files/mainbasic.tex

\documentclass{article}
\usepackage{graphicx} % Required for inserting images

\title{<%= project_name %>}
\author{<%= user.first_name %> <%= user.last_name %>}
\date{<%= month %> <%= year %>}

\begin{document}

\maketitle

\section{Introduction}

\end{document}