How to extract author and year data when using `elsart-num` bibliography style?

Question

elsarticle seems to use natbib for managing citations. However, when I try to extract author and year data using \citeauthor and \citeyear, I do not get any errors but the output returns (author?) and (year?)

\begin{filecontents}{sample.bib}
@inproceedings{aldaoudeyeh2020statistical,
    title={Statistical Analysis of Wind Power Using Weibull Distribution to Maximize Energy Yield},
    author={Aldaoudeyeh, Al-Motasem I and Alzaareer, Khaled},
    booktitle={2020 IEEE PES/IAS PowerAfrica},
    pages={1--5},
    year={2020},
    organization={IEEE}
}
\end{filecontents}

\documentclass[]{elsarticle}

\begin{document}

\citeauthor{aldaoudeyeh2020statistical}
\citeyear{aldaoudeyeh2020statistical}

\newpage
\bibliographystyle{elsart-num}
\bibliography{sample}

\end{document}