`\makelapbox` 的报错问题

MWE

我看手册是可以 \makelapbox{material}，但是

\documentclass{ctexart}
\makeatletter
\@ifundefined{input@path}{\let\input@path\@empty}{}
\g@addto@macro\input@path{{./module}{./library}{./lt3ekeys}{./cus-doc}{./cus-doc-aux}}
\makeatother
\usepackage{cus}

\begin{document}

左边的文字\makelapbox{测试}右边的文字

\end{document}

xelatex 后报错

Missing number, treated as zero.
<to be read again>

Sophanatprime / cus

`\makelapbox` 的报错问题 #36

MWE