title: Latex cannot add author
body: <p>I am using overleaf to edit my article. Here is my content:</p>
  
  <pre class="lang-latex prettyprint-override"><code>\documentclass{article}
  % if you need to pass options to natbib, use, e.g.:
  %     \PassOptionsToPackage{numbers, compress}{natbib}
  % before loading neurips_2019   
  
  % ready for submission
  % \usepackage{neurips_2019} 
  
  % to compile a preprint version, e.g., for submission to arXiv, add add the
  % [preprint] option:
  %     \usepackage[preprint]{neurips_2019}   
  
  % to compile a camera-ready version, add the [final] option, e.g.:
  \usepackage[]{neurips_2019} 
  
  % to avoid loading the natbib package, add option nonatbib:
  %     \usepackage[nonatbib]{neurips_2019}   
  
  \usepackage[utf8]{inputenc} % allow utf-8 input
  \usepackage[T1]{fontenc}    % use 8-bit T1 fonts
  \usepackage{hyperref}       % hyperlinks
  \usepackage{url}            % simple URL typesetting
  \usepackage{booktabs}       % professional-quality tables
  \usepackage{amsfonts}       % blackboard math symbols
  \usepackage{nicefrac}       % compact symbols for 1/2, etc.
  \usepackage{microtype}      % microtypography
  \usepackage{graphicx}
  \begin{document}
  \title{On the General Molecular Theory of Heat}
  \author{A. Einstein}
  \maketitle
  \end{document}
  </code></pre>
  
  <p>Here is what it looks like: 
  <a href="https://i.stack.imgur.com/ibrVb.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ibrVb.png" alt="enter image description here"></a></p>
  
  <p>As you can see, I have already set the author to be A. Einstein, but it still shows the default anonymous author. I wonder why would that happen and how should I fix it?</p>
  
  <p>Thanks!</p>