How I can change the distance between the text and footnote rule in this example:
\documentclass[11pt]{book}
\RequirePackage{luatex85}
\usepackage[paperwidth=140mm,paperheight=210mm,top=25mm,bottom=20mm,left=20mm,right=20mm,heightrounded]{geometry}
\usepackage{kantlipsum}
\addtolength{\footskip}{22mm}
\makeatletter
\def\footnoterule{\kern-3mm\kern-3\p@
\hrule \@width 2in \kern 2.6\p@
\kern 3mm}
\makeatother
\begin{document}
Some text\footnote{Footnote example}
\kant[1-3]
\end{document}