Beamer + apacite: Citation undefined

Question

I am doing a presentation with the beamer class using the metropolis theme. Currently I am using RStudio and compile the file with XeLaTeX. Texmaker is an alternative.

How to make biblatex behave like apacite? - did not work for me. May be I need to compile with more than just 1x XeLaTeX?

I would prefer to use Bibtex with apacite being able to just include a .bib file for \bibliography. However, I read that there exist some conflicts?

Errors:
- Rerun to get \PageLabels entry
- Citation ... undefined

\documentclass{beamer}
\usepackage{appendixnumberbeamer}

% various symbols
\usepackage{gensymb}

% bibliographystyle
\usepackage{apacite}

% Bilbliography
\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
@Misc{Ref1,
  author = {{Test author}},
  title  = {Test title},
  year   = {2016},
  url    = {http://testurl.com=},
}
\end{filecontents}

\usetheme[sectionpage = progressbar, numbering = fraction]{metropolis} 

% title preface
\title{Title}

\begin{document}
\maketitle

% ------------------------------------------------------------------------------
\begin{frame}{Frame1}
    \cite{Ref1}
\end{frame}

% ------------------------------------------------------------------------------
\begin{frame}[allowframebreaks]{Bibliography}%in case more than 1 slide needed
{\footnotesize
\bibliographystyle{apacite}
\bibliography{\jobname}
}
\end{frame}