頁碼為頁尾中的 CurrPageTotalPages

\documentclass[12pt]{article}

\usepackage{lastpage}
\usepackage{fancyhdr}
\usepackage{graphicx}
\usepackage{lipsum} % for dummy text

\pagestyle{myheadings}
\pagestyle{fancy}
\fancyhf{}

\setlength{\headheight}{30pt}

\renewcommand{\headrulewidth}{1pt}
\renewcommand{\footrulewidth}{2pt}

\lhead{\includegraphics[width=1cm]{example-image-a}}
\rhead{}

\lfoot{ABC}
\rfoot{\thepage/\pageref{LastPage}}

\begin{document}

\section{First section}
\subsection{One}
 \lipsum[1-3]
 
\end{document}