\tkzDrawLine doesn't print node

\tkzDrawLine doesn't print node

I've made this drawing, but I can manage to place the node $m$ to the
line. Any suggestions? Thanks in advance

\documentclass[a4paper]{article}
\usepackage{pgfplots}
\usepackage{tkz-euclide}
\usetkzobj{all}
\begin{document}
\begin{center}
\begin{tikzpicture}
\coordinate (M) at (0,0) ;
\coordinate (A) at (canvas polar cs:angle=90,radius=3cm);
\coordinate (B) at (canvas polar cs:angle=20,radius=3cm) ;
\draw (M) circle (3cm);
\draw (A) -- (B) ;
\tkzDefMidPoint(A,B) \tkzGetPoint{P}
\draw (A) -- (P) node[midway,sloped] {$// $} ;
\draw (P) -- (B) node[midway,sloped] {$// $} ;
\tkzDrawLine[add = 0.5 and 1.6](P,M) node {m}; %PROBLEM%
\tkzDrawPoints(A,B,M);
\tkzLabelPoints(B,M);
\tkzLabelPoints[above](A);
\end{tikzpicture}
\end{center}
\end{document}