# How to centering captions in figure environment when using els-cas template?

I'm using the els-cas template to write a paper aiming at Elsevier journals. I want to use the command "\captionsetup" in "caption" package to customize my caption in "Figure" environment. How can I do to achieve the results: \captionsetup{figurename=Fig.,labelsep=period,font={bf,footnotesize},center}?

\documentclass[a4paper]{cas-sc}
\usepackage[authoryear,longnamesfirst]{natbib}

\usepackage{caption}% caption package
\captionsetup{figurename=Fig.,labelsep=period,font={bf,footnotesize},center}

\begin{document}

\title [mode = title]{This is a specimen $a_b$ title}
\maketitle

\begin{figure}[pos=htbp]
\centering
\includegraphics{Fig1}
\caption{My caption.} %%%%%% My caption content is short
\end{figure}
\end{document}


The resultant caption format in the output PDF is

which is the default formatting preset in the els-cas-sc class file.

Could any expert help me? Thank you very much!