I use a template from school incluing five parts——main.tex, main.pdf, sample.bib, UCLISH.cls, Figures folder. I want to run the main.tex, but there is an error showing ! LaTeX Error: File `main-words.sum' not found. I looked into the UCLISH.cls and found there is a string of codes:
\newcommand{\quickwordcount}[1]{%
\immediate\write18{texcount -sum=1 -q -1 -merge #1.tex > #1-words.sum }%
\input{#1-words.sum}%
}
Maybe these codes are related to this problem. But I do not know how to deal with it. Do I need to download any packages?



pdflatex --shell-escapeto allow system commands. – David Carlisle May 03 '23 at 08:34